National Library of Energy BETA

Sample records for dark matter searches

  1. Axion Dark Matter Searches

    E-Print Network [OSTI]

    I. Stern

    2014-03-21

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  2. Axion Dark Matter Searches

    E-Print Network [OSTI]

    Stern, I

    2014-01-01

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  3. Axion Dark Matter Searches

    E-Print Network [OSTI]

    I. Stern

    2015-11-17

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  4. Dark matter searches

    E-Print Network [OSTI]

    Laura Baudis

    2015-09-02

    One of the major challenges of modern physics is to decipher the nature of dark matter. Astrophysical observations provide ample evidence for the existence of an invisible and dominant mass component in the observable universe, from the scales of galaxies up to the largest cosmological scales. The dark matter could be made of new, yet undiscovered elementary particles, with allowed masses and interaction strengths with normal matter spanning an enormous range. Axions, produced non-thermally in the early universe, and weakly interacting massive particles (WIMPs), which froze out of thermal equilibrium with a relic density matching the observations, represent two well-motivated, generic classes of dark matter candidates. Dark matter axions could be detected by exploiting their predicted coupling to two photons, where the highest sensitivity is reached by experiments using a microwave cavity permeated by a strong magnetic field. WIMPs could be directly observed via scatters off atomic nuclei in underground, ultra low-background detectors, or indirectly, via secondary radiation produced when they pair annihilate. They could also be generated at particle colliders such as the LHC, where associated particles produced in the same process are to be detected. After a brief motivation and an introduction to the phenomenology of particle dark matter detection, I will discuss the most promising experimental techniques to search for axions and WIMPs, addressing their current and future science reach, as well as their complementarity.

  5. The Search for Dark Matter

    SciTech Connect (OSTI)

    Orrell, John

    2013-11-20

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  6. The Search for Dark Matter

    ScienceCinema (OSTI)

    Orrell, John

    2014-07-24

    More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

  7. Dark matter searches

    E-Print Network [OSTI]

    Baudis, Laura

    2015-01-01

    One of the major challenges of modern physics is to decipher the nature of dark matter. Astrophysical observations provide ample evidence for the existence of an invisible and dominant mass component in the observable universe, from the scales of galaxies up to the largest cosmological scales. The dark matter could be made of new, yet undiscovered elementary particles, with allowed masses and interaction strengths with normal matter spanning an enormous range. Axions, produced non-thermally in the early universe, and weakly interacting massive particles (WIMPs), which froze out of thermal equilibrium with a relic density matching the observations, represent two well-motivated, generic classes of dark matter candidates. Dark matter axions could be detected by exploiting their predicted coupling to two photons, where the highest sensitivity is reached by experiments using a microwave cavity permeated by a strong magnetic field. WIMPs could be directly observed via scatters off atomic nuclei in underground, ultr...

  8. Dark Matter Searches

    E-Print Network [OSTI]

    Laura Baudis

    2005-11-29

    More than 90% of matter in the Universe could be composed of heavy particles, which were non-relativistic, or 'cold', when they froze-out from the primordial soup. I will review current searches for these hypothetical particles, both via interactions with nuclei in deep underground detectors, and via the observation of their annihilation products in the Sun, galactic halo and galactic center.

  9. Indirect searches for neutralino dark matter

    E-Print Network [OSTI]

    Joakim Edsjo

    2002-11-15

    There is mounting evidence for dark matter in the Universe and one of the favourite dark matter candidates is the neutralino, which naturally appears as the lightest supersymmetric particle (LSP) in many supersymmetric extensions of the standard model. The neutralino has the desired properties to be a good dark matter candidate and we will here review the different indirect searches for neutralino dark matter and discuss the implications on these from recent direct searches.

  10. Dark Matter Searche with GLAST

    E-Print Network [OSTI]

    E. Nuss

    2007-04-20

    The Gamma-Ray Large Area Space Telescope (GLAST), scheduled to be launched in fall 2007, is the next generation satellite for high-energy gamma-ray astronomy. The Large Area Telescope (LAT), GLAST main instrument, with a wide field of view (> 2 sr), a large effective area (> 8000 cm^2 at 1 GeV) and 20 MeV - 300 GeV energy range, will provide excellent high energy gamma-ray observations for Dark Matter searches. In this paper we examine the potential of the LAT to detect gamma-rays coming from WIMPS annihilation in the context of supersymmetry. As an example, two search regions are investigated: the galactic center and the galactic satellites.

  11. DEAP-3600 Dark Matter Search

    E-Print Network [OSTI]

    P. -A. Amaudruz; M. Batygov; B. Beltran; J. Bonatt; M. G. Boulay; B. Broerman; J. F. Bueno; A. Butcher; B. Cai; M. Chen; R. Chouinard; B. T. Cleveland; K. Dering; J. DiGioseffo; F. Duncan; T. Flower; R. Ford; P. Giampa; P. Gorel; K. Graham; D. R. Grant; E. Guliyev; A. L. Hallin; M. Hamstra; P. Harvey; C. J. Jillings; M. Ku?niak; I. Lawson; O. Li; P. Liimatainen; P. Majewski; A. B. McDonald; T. McElroy; K. McFarlane; J. Monroe; A. Muir; C. Nantais; C. Ng; A. J. Noble; C. Ouellet; K. Palladino; P. Pasuthip; S. J. M. Peeters; T. Pollmann; W. Rau; F. Retière; N. Seeburn; K. Singhrao; P. Skensved; B. Smith; T. Sonley; J. Tang; E. Vázquez-Jáuregui; L. Veloce; J. Walding; M. Ward

    2014-10-27

    The DEAP-3600 experiment is located 2 km underground at SNOLAB, in Sudbury, Ontario. It is a single-phase detector that searches for dark matter particle interactions within a 1000-kg fiducial mass target of liquid argon. A first generation prototype detector (DEAP-1) with a 7-kg liquid argon target mass demonstrated a high level of pulse-shape discrimination (PSD) for reducing $\\beta$/$\\gamma$ backgrounds and helped to develop low radioactivity techniques to mitigate surface-related $\\alpha$ backgrounds. Construction of the DEAP-3600 detector is nearly complete and commissioning is starting in 2014. The target sensitivity to spin-independent scattering of Weakly Interacting Massive Particles (WIMPs) on nucleons of 10$^{-46}$ cm$^2$ will allow one order of magnitude improvement in sensitivity over current searches at 100 GeV WIMP mass. This paper presents an overview and status of the DEAP-3600 project and discusses plans for a future multi-tonne experiment, DEAP-50T.

  12. Identifying dark matter interactions in monojet searches

    SciTech Connect (OSTI)

    Agrawal, Prateek; Rentala, Vikram

    2014-05-01

    We study the discrimination of quark-initiated jets from gluon-initiated jets in monojet searches for dark matter using the technique of averaged jet energy profiles. We demonstrate our results in the context of effective field theories of dark matter interactions with quarks and gluons, but our methods apply more generally to a wide class of models. Different effective theories of dark matter and the standard model backgrounds each have a characteristic quark/gluon fraction for the leading jet. When used in conjunction with the traditional cut-and-count monojet search, the jet energy profile can be used to set stronger bounds on contact interactions of dark matter. In the event of a discovery of a monojet excess at the 14 TeV LHC, contact interactions between dark matter with quarks or with gluons can be differentiated at the 95% confidence level. For a given rate at the LHC, signal predictions at direct detection experiments for different dark matter interactions can span five orders of magnitude. The ability to identify these interactions allows us to make a tighter connection between LHC searches and direct detection experiments.

  13. The CRESST Dark Matter Search

    E-Print Network [OSTI]

    B. Majorovits; G. Angloher; C. Bucci; P. Christ; C. Cozzini; F. von Feilitzsch; D. Hauff; S. Henry; Th. Jagemann; J. Jochum; H. Kraus; V. Mikhailik; J. Ninkovic; F. Petricca; W. Potzel; F. Proebst; Y. Ramachers; M. Razeti; W. Rau; W. Seidel; M. Stark; L. Stodolsky; A. J. B. Tolhurst; D. Wahl; W. Westphal; H. Wulandari

    2004-11-15

    We present first competitive results on WIMP dark matter using the phonon-light-detection technique. A particularly strong limit for WIMPs with coherent scattering results from selecting a region of the phonon-light plane corresponding to tungsten recoils. The observed count rate in the neutron band is compatible with the rate expected from neutron background. CRESST is presently being upgraded with a 66 channel SQUID readout system, a neutron shield and a muon veto system. This results in a significant improvement in sensitivity.

  14. Indirect dark matter search with AMS-02

    E-Print Network [OSTI]

    S. Di Falco

    2006-07-06

    The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station, will provide data on cosmic radiations in the energy range from 0.5 GeV to 3 TeV. The main physics goals are the anti-matter and the dark matter searches. Observations and cosmology indicate that the Universe may include a large amount of unknown Dark Matter. It should be composed of non baryonic Weakly Interacting Massive Particles (WIMP). In R-parity conserving models a good WIMP candidate is the lightest SUSY particle. AMS offers a unique opportunity to study simultaneously SUSY dark matter in three decay channels resulting from the neutralino annihilation: e+, antiproton and gamma. Either in the SUSY frame and in alternative scenarios (like extra-dimensions) the expected flux sensitivities as a function of energy in 3 year exposure for the e+/e- ratio, gamma and antiproton yields are presented.

  15. Indirect and direct search for dark matter

    E-Print Network [OSTI]

    Michael Klasen; Martin Pohl; Günter Sigl

    2015-07-14

    The majority of the matter in the universe is still unidentified and under investigation by both direct and indirect means. Many experiments searching for the recoil of dark-matter particles off target nuclei in underground laboratories have established increasingly strong constraints on the mass and scattering cross sections of weakly interacting particles, and some have even seen hints at a possible signal. Other experiments search for a possible mixing of photons with light scalar or pseudo-scalar particles that could also constitute dark matter. Furthermore, annihilation or decay of dark matter can contribute to charged cosmic rays, photons at all energies, and neutrinos. Many existing and future ground-based and satellite experiments are sensitive to such signals. Finally, data from the Large Hadron Collider at CERN are scrutinized for missing energy as a signature of new weakly interacting particles that may be related to dark matter. In this review article we summarize the status of the field with an emphasis on the complementarity between direct detection in dedicated laboratory experiments, indirect detection in the cosmic radiation, and searches at particle accelerators.

  16. An Ultimate Target for Dark Matter Searches

    E-Print Network [OSTI]

    Kfir Blum; Yanou Cui; Marc Kamionkowski

    2014-12-10

    The combination of S-matrix unitarity and the dynamics of thermal freeze-out for massive relic particles (denoted here simply by WIMPs) implies a lower limit on the density of such particles, that provide a (potentially sub-dominant) contribution to dark matter. This then translates to lower limits to the signal rates for a variety of techniques for direct and indirect detection of dark matter. For illustration, we focus on models where annihilation is s-wave dominated. We derive lower limits to the flux of gamma-rays from WIMP annihilation at the Galactic center; direct detection of WIMPs; energetic neutrinos from WIMP annihilation in the Sun; and the effects of WIMPs on the angular power spectrum and frequency spectrum of the cosmic microwave background radiation. The results suggest that a variety of dark-matter-search techniques may provide interesting avenues to seek new physics, even if WIMPs do not constitute all the dark matter. While the limits are quantitatively some distance from the reach of current measurements, they may be interesting for long-range planning exercises.

  17. Dark Matter Searches with Representing the

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    · Supernova Remnants · Unidentified Gamma-ray Sources · Gamma-Ray Bursts · Solar Physics · Dark Matter #12;SCIPP talk Larry Wai / SLAC 4 Talk overview 1. What is GLAST? 2. How does dark matter shine in gamma rays? 3. Where should we look for dark matter with GLAST? #12;SCIPP talk Larry Wai / SLAC 5 GLAST

  18. Transition Radiation Detector to Search for Dark Matter in Space

    E-Print Network [OSTI]

    Roma "La Sapienza", Università di

    The AMS-02 Transition Radiation Detector to Search for Dark Matter in Space The AMSThe AMS--0202 Transition Radiation DetectorTransition Radiation Detector to Search for Dark Matter in Spaceto Search.it On behalf of the AMS collaboration Transition Radiation DetectorTransition Radiation Detector Transition

  19. A time domain phonon pulse fitting analysis for the cryogenic dark matter search experiment

    E-Print Network [OSTI]

    Schlupf, Chandler

    2014-01-01

    Dark matter makes up 85% of the known matter in the Universe, but the exact nature of dark matter remains unknown. The Cryogenic Dark Matter Search experiment, CDMS, attempts to directly detect the leading candidate dark ...

  20. Searching for Cosmic Dark Matter in the Sewers of Chicago

    E-Print Network [OSTI]

    Collar, Juan I.

    Searching for Cosmic Dark Matter in the Sewers of Chicago Presenter: Juan Collar Time & Date: 7 for Cosmic Dark Matter in the Sewers of Chicago Presenter: Juan Collar Time & Date: 7-9 PM Monday September to catch particles that may or may not be there, to the exotic venues (including sewers, mines thousands

  1. Direct Search for Low Mass Dark Matter Particles with CCDs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Barreto, J.; Cease, H.; Diehl, H. T.; Estrada, J.; Flaugher, B.; Harrison, N.; Jones, J.; Kilminster, B.; Molina, J.; Smith, J.; et al

    2012-05-15

    A direct dark matter search is performed using fully-depleted high-resistivity CCD detectors. Due to their low electronic readout noise (RMS ~7 eV) these devices operate with a very low detection threshold of 40 eV, making the search for dark matter particles with low masses (~5 GeV) possible. The results of an engineering run performed in a shallow underground site are presented, demonstrating the potential of this technology in the low mass region.

  2. Dark matter searches with cosmic antideuterons: status and perspectives

    E-Print Network [OSTI]

    Fornengo, N; Vittino, A

    2013-01-01

    The search for antideuterons in cosmic rays has been proposed as a promising channel for dark matter indirect detection, especially for dark matter particles with a low or intermediate mass. With the current operational phase of the AMS-02 experiment and the ongoing development of a future dedicated experiment, the General Antiparticle Spectrometer (GAPS), there are exciting prospects for a dark matter detection in the near future. In this paper we develop a detailed and complete re-analysis of the cosmic-ray antideuteron signal, by discussing the main relevant issues related to antideuteron production and propagation through the interstellar medium and the heliosphere. In particular, we first critically revisit the coalescence mechanism for antideuteron production in dark matter annihilation processes. Then, since antideuteron searches have their best prospects of detection at low kinetic energies where the effect of the solar wind and magnetic field are most relevant, we address the impact of solar modulati...

  3. Systematic uncertainties from halo asphericity in dark matter searches

    SciTech Connect (OSTI)

    Bernal, Nicolás; Forero-Romero, Jaime E.; Garani, Raghuveer; Palomares-Ruiz, Sergio E-mail: je.forero@uniandes.edu.co E-mail: sergio.palomares.ruiz@ific.uv.es

    2014-09-01

    Although commonly assumed to be spherical, dark matter halos are predicted to be non-spherical by N-body simulations and their asphericity has a potential impact on the systematic uncertainties in dark matter searches. The evaluation of these uncertainties is the main aim of this work, where we study the impact of aspherical dark matter density distributions in Milky-Way-like halos on direct and indirect searches. Using data from the large N-body cosmological simulation Bolshoi, we perform a statistical analysis and quantify the systematic uncertainties on the determination of local dark matter density and the so-called J factors for dark matter annihilations and decays from the galactic center. We find that, due to our ignorance about the extent of the non-sphericity of the Milky Way dark matter halo, systematic uncertainties can be as large as 35%, within the 95% most probable region, for a spherically averaged value for the local density of 0.3-0.4 GeV/cm {sup 3}. Similarly, systematic uncertainties on the J factors evaluated around the galactic center can be as large as 10% and 15%, within the 95% most probable region, for dark matter annihilations and decays, respectively.

  4. Dark Matter Search with CUORE-0 and CUORE

    SciTech Connect (OSTI)

    Aguirre, C.P.; Artusa, D.R.; Avignone, F.T.; Azzolini, O.; Balata, M.; Banks, T.I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; Brofferio, C.; Bucci, C.; Cai, X.Z.; Camacho, A.; Canonica, L.; Cao, X.; Capelli, S.; Carbone, L.; Cardani, L.; Carrettoni, M.; Casali, N.; Chiesa, D.; Chott, N.; Clemenza, M.; Cosmelli, C.; Cremonesi, O.; Creswick, R.J.; Dafinei, I.; Dally, A.; Datskov, V.; De Biasi, A.; Deninno, M.M.; Di Domizio, S.; di Vacri, M.L.; Ejzak, L.; Fang, D.Q.; Farach, H.A.; Faverzani, M.; Fernandes, G.; Ferri, E.; Ferroni, F.; Fiorini, E.; Franceschi, M.A.; Freedman, S.J.; Fujikawa, B.K.; Giachero, A.; Gironi, L.; Giuliani, A.; Goett, J.; Gorla, P.; Gotti, C.; Gutierrez, T.D.; Haller, E.E.; Han, K.; Heeger, K.M.; Hennings-Yeomans, R.; Huang, H.Z.; Kadel, R.; Kazkaz, K.; Keppel, G.; Kolomensky, Yu.G.; Li, Y.L.; Ligi, C.; Liu, X.; Ma, Y.G.; Maiano, C.; Maino, M.; Martinez, M.; Maruyama, R.H.; Mei, Y.; Moggi, N.; Morganti, S.; Napolitano, T.; Nisi, S.; Nones, C.; Norman, E.B.; Nucciotti, A.; O’Donnell, T.; Orio, F.; Orlandi, D.; Ouellet, J.L.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Piperno, G.; Pira, C.; Pirro, S.; Previtali, E.; Rampazzo, V.; Rosenfeld, C.; Rusconi, C.; Sala, E.; Sangiorgio, S.; Scielzo, N.D.; Sisti, M.; Smith, A.R.; Taffarello, L.; Tenconi, M.; Terranova, F.; Tian, W.D.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wang, B.S.; Wang, H.W.; Wielgus, L.; Wilson, J.; Winslow, L.A.; Wise, T.; Woodcraft, A.; Zanotti, L.; Zarra, C.; Zhu, B.X.; Zucchelli, S.

    2015-01-01

    The Cryogenic Underground Observatory for Rare Events (CUORE) is a ton-scale experiment made of TeO2 bolometers that will probe the neutrinoless double beta decay of 130Te. Excellent energy resolution, low threshold and low background make CUORE sensitive to nuclear recoils, allowing a search for dark matter interactions. With a total mass of 741 kg of TeO2, CUORE can search for an annual modulation of the counting rate at low energies. We present data obtained with CUORE-like detectors and the prospects for a dark matter search in CUORE-0, a 40-kg prototype, and CUORE.

  5. Dark matter search with CUORE-0 and CUORE

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aguirre, C. P.; Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; et al

    2015-01-01

    The Cryogenic Underground Observatory for Rare Events (CUORE) is a ton-scale experiment made of TeO? bolometers that will probe the neutrinoless double beta decay of ¹³?Te. Excellent energy resolution, low threshold and low background make CUORE sensitive to nuclear recoils, allowing a search for dark matter interactions. With a total mass of 741 kg of TeO?, CUORE can search for an annual modulation of the counting rate at low energies. We present data obtained with CUORE-like detectors and the prospects for a dark matter search in CUORE-0, a 40-kg prototype, and CUORE.

  6. Searching for WISPy cold dark matter with a dish antenna

    SciTech Connect (OSTI)

    Horns, Dieter; Jaeckel, Joerg; Lindner, Axel; Ringwald, Andreas; Lobanov, Andrei; Redondo, Javier E-mail: jjaeckel@thphys.uni-heidelberg.de E-mail: alobanov@mpifr-bonn.mpg.de E-mail: andreas.ringwald@desy.de

    2013-04-01

    The cold dark matter of the Universe may be comprised of very light and very weakly interacting particles, so-called WISPs. Two prominent examples are hidden photons and axion-like particles. In this note we propose a new technique to sensitively search for this type of dark matter with dish antennas. The technique is broadband and allows to explore a whole range of masses in a single measurement.

  7. Search for Low-Mass Dark Matter at BABAR (Journal Article) |...

    Office of Scientific and Technical Information (OSTI)

    Search for Low-Mass Dark Matter at BABAR Citation Details In-Document Search Title: Search for Low-Mass Dark Matter at BABAR You are accessing a document from the Department of...

  8. Search for Low-Mass Dark Matter at BABAR (Journal Article) |...

    Office of Scientific and Technical Information (OSTI)

    Search for Low-Mass Dark Matter at BABAR Citation Details In-Document Search Title: Search for Low-Mass Dark Matter at BABAR Authors: Echenard, Bertrand ; Caltech Publication...

  9. Composite dark matter and direct-search experiments

    E-Print Network [OSTI]

    Quentin Wallemacq

    2015-12-18

    We reinterpret the results of the direct searches for dark matter in terms of composite dark matter, i.e. dark matter particles that form neutral bound states, generically called dark atoms, either with ordinary particles, or with other dark matter particles. Three different scenarios are investigated: the O-helium scenario, milli- interacting dark matter and dark anti-atoms. In each of them, dark matter interacts sufficiently strongly with terrestrial matter to be stopped in it before reaching underground detectors. As they drift towards the center of the earth by gravity, these thermal dark atoms are radiatively captured by the atoms of the active medium of underground detectors, which causes the emission of photons that produce the signals through their interactions with the electrons of the medium. This provides a way of reinterpreting the results in terms of electron recoils instead of nuclear recoils. The detailed study of the interactions of O-helium with ordinary matter shows that it is not an acceptable candidate for dark matter because of the absence of a repulsion mechanism preventing it from falling into the deep nuclear wells of nuclei. The two other models involve milli-charges and are able to reconcile the most contradictory experiments. We determine, for each model, the regions in the parameter space that reproduce the experiments with positive results in full consistency with the constraints of the experiments with negative results. We also pay attention to the experimental and observational constraints on milli-charges and discuss some typical signatures of the models that could be used to test them.

  10. Simplified Models for Dark Matter Searches at the LHC

    E-Print Network [OSTI]

    Jalal Abdallah; Henrique Araujo; Alexandre Arbey; Adi Ashkenazi; Alexander Belyaev; Joshua Berger; Celine Boehm; Antonio Boveia; Amelia Brennan; Jim Brooke; Oliver Buchmueller; Matthew Buckley; Giorgio Busoni; Lorenzo Calibbi; Sushil Chauhan; Nadir Daci; Gavin Davies; Isabelle De Bruyn; Paul De Jong; Albert De Roeck; Kees de Vries; Daniele Del Re; Andrea De Simone; Andrea Di Simone; Caterina Doglioni; Matthew Dolan; Herbi Dreiner; John Ellis; Sarah Eno; Erez Etzion; Malcolm Fairbairn; Brian Feldstein; Henning Flaecher; Feng Eric; Marie-Hélène Genest; Loukas Gouskos; Johanna Gramling; Ulrich Haisch; Roni Harnik; Anthony Hibbs; Siewyan Hoh; Walter Hopkins; Valerio Ippolito; Thomas Jacques; Felix Kahlhoefer; Valentin V. Khoze; Russell Kirk; Andreas Korn; Khristian Kotov; Shuichi Kunori; Greg Landsberg; Sebastian Liem; Tongyan Lin; Steven Lowette; Robyn Lucas; Luca Malgeri; Sarah Malik; Christopher McCabe; Alaettin Serhan Mete; Enrico Morgante; Stephen Mrenna; Yu Nakahama; Dave Newbold; Karl Nordstrom; Priscilla Pani; Michele Papucci; Sophio Pataraia; Bjoern Penning; Deborah Pinna; Giacomo Polesello; Davide Racco; Emanuele Re; Antonio Walter Riotto; Thomas Rizzo; David Salek; Subir Sarkar; Steven Schramm; Patrick Skubic; Oren Slone; Juri Smirnov; Yotam Soreq; Timothy Sumner; Tim M. P. Tait; Marc Thomas; Ian Tomalin; Christopher Tunnell; Alessandro Vichi; Tomer Volansky; Neal Weiner; Stephen M. West; Monika Wielers; Steven Worm; Itay Yavin; Bryan Zaldivar; Ning Zhou; Kathryn Zurek

    2015-06-09

    This document outlines a set of simplified models for dark matter and its interactions with Standard Model particles. It is intended to summarize the main characteristics that these simplified models have when applied to dark matter searches at the LHC, and to provide a number of useful expressions for reference. The list of models includes both s-channel and t-channel scenarios. For s-channel, spin-0 and spin-1 mediation is discussed, and also realizations where the Higgs particle provides a portal between the dark and visible sectors. The guiding principles underpinning the proposed simplified models are spelled out, and some suggestions for implementation are presented.

  11. Dark Matter Benchmark Models for Early LHC Run-2 Searches. Report of the ATLAS/CMS Dark Matter Forum

    SciTech Connect (OSTI)

    Abercrombie, Daniel

    2015-07-06

    One of the guiding principles of this report is to channel the efforts of the ATLAS and CMS collaborations towards a minimal basis of dark matter models that should influence the design of the early Run-2 searches. At the same time, a thorough survey of realistic collider signals of Dark Matter is a crucial input to the overall design of the search program.

  12. Search for Dark Matter with the AMS experiment

    SciTech Connect (OSTI)

    Palomares, Carmen [CIEMAT Avda Complutense 22. 28040 Madrid (Spain)

    2006-11-28

    The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed to operate on the International Space Station (ISS). The aim of AMS is the direct detection of charged particles in the rigidity range from 0.5 GV to few TV erform high statistics studies of cosmic rays in space and search for antimatter and dark matter. The most favored candidate to conform the cold dark matter is a non-relativistic interacting, massive particle (WIMP). AMS will be able to detect simultaneously the main signatures of the annihilation of such as particle: {gamma}, e+,p-bar in an energy range never reached before.

  13. Searching for dark matter sterile neutrino in laboratory

    E-Print Network [OSTI]

    Fedor Bezrukov; Mikhail Shaposhnikov

    2007-02-13

    If the dark matter of the Universe is made of sterile neutrinos with the mass in keV region they can be searched for with the help of X-ray satellites. We discuss the prospects of laboratory experiments that can be competitive and complimentary to Space missions. We argue that the detailed study of beta decays of tritium and other nuclei with the help of Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) can potentially enter into interesting parameter range and even supersede the current astronomical bounds on the properties of dark matter sterile neutrino.

  14. Search for Earth-Mass Planets and Dark Matter, Too

    E-Print Network [OSTI]

    S. H. Rhie; D. P. Bennett

    1996-07-12

    Gravitational microlensing is known for baryoninc dark matter searches. Here we show that microlensing also provides a unique tool for the detection of low mass planets (such as earths and neptunes) from the ground. A planetary system forms a binary lens (or, a multi-point lens), and we can determine the mass ratio of the planet with respect to the star and relative distance ($=$ separation/Einstein ring radius) between the star and planet. Such a microlenisng planet search project requires a $\\approx 2$ m survey telescope, and a network of $1.5-2$ m follow-up telescopes capable of monitoring stars in the Bulge on a 24-hour basis. During the off-season of the Galactic bulge, this network can be used for dark matter search by monitoring the stars in the LMC and SMC.

  15. XENON dark matter searches: Results and the future

    SciTech Connect (OSTI)

    Brown, Andrew [Physics Department, Purdue University - 525 Northwestern Ave., West Lafayette, IN 47907 (United States); Collaboration: XENON Collaboration

    2014-06-24

    XENON100 is a dark matter search experiment looking for elastic WIMP scattering using a 62 kg liquid target. WIMP search data from XENON100 published in 2012 has set the world's strongest limits on WIMP-nucleus spinindependent, elastic scattering. It has also set the strongest limits on WIMP-nucleus spin-dependent scattering considering neutron scattering only, and competitive limits considering proton scattering only. The successor experiment to XENON100, XENON1T, is currently under construction, with commissioning scheduled to begin in 2014. XENON1T's design goal is a 100 fold increase in sensitivity for elastic WIMP searches over XENON100.

  16. DARWIN: dark matter WIMP search with noble liquids

    E-Print Network [OSTI]

    Laura Baudis

    2010-12-21

    DARWIN (DARk matter WImp search with Noble liquids) is an R&D and design study towards the realization of a multi-ton scale dark matter search facility in Europe, based on the liquid argon and liquid xenon time projection chamber techniques. Approved by ASPERA in late 2009, DARWIN brings together several European and US groups working on the existing ArDM, XENON and WARP experiments with the goal of providing a technical design report for the facility by early 2013. DARWIN will be designed to probe the spin-independent WIMP-nucleon cross section region below 10-47cm^2 and to provide a high-statistics measurement of WIMP interactions in case of a positive detection in the intervening years. After a brief introduction, the DARWIN goals, components, as well as its expected physics reach will be presented.

  17. Hot and Cold Dark Matter Search with GENIUS

    E-Print Network [OSTI]

    Laura Baudis; Alexander Dietz; Gerd Heusser; Hans Volker Klapdor-Kleingrothaus; Bela Majorovits; Herbert Strecker

    2000-05-30

    GENIUS is a proposal for a large volume detector to search for rare events. An array of 40-400 'naked' HPGe detectors will be operated in a tank filled with ultra-pure liquid nitrogen. After a description of performed technical studies of detector operation in liquid nitrogen and of Monte Carlo simulations of expected background components, the potential of GENIUS for detecting WIMP dark matter, the neutrinoless double beta decay in 76-Ge and low-energy solar neutrinos is discussed.

  18. A dark matter search with MALBEK

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Giovanetti, G. K.; Abgrall, N.; Aguayo, E.; Avignone, III, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; et al

    2015-01-01

    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of ??Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surfacemore »event contamination when searching for a WIMP signal.« less

  19. A Dark Matter Search with MALBEK

    SciTech Connect (OSTI)

    Giovanetti, G.K.; Abgrall, N.; Aguayo, E.; Avignone, F.T.; Barabash, A.S.; Bertrand, F.E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A.S.; Chan, Y-D.; Christofferson, C.D.; Combs, D.C.; Cuesta, C.; Detwiler, J.A.; Doe, P.J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S.R.; Fast, J.E.; Finnerty, P.; Fraenkle, F.M.; Galindo-Uribarri, A.; Goett, J.; Green, M.P.; Gruszko, J.; Guiseppe, V.E.; Gusev, K.; Hallin, A.L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E.W.; Howard, S.; Howe, M.A.; Keeter, K.J.; Kidd, M.F.; Kochetov, O.; Konovalov, S.I.; Kouzes, R.T.; LaFerriere, B.D.; Leon, J.; Leviner, L.E.; Loach, J.C.; MacMullin, J.; MacMullin, S.; Martin, R.D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J.L.; O'Shaughnessy, C.; Overman, N.R.; Phillips, D.G.; Poon, A.W.P.; Pushkin, K.; Radford, D.C.; Rager, J.; Rielage, K.; Robertson, R.G.H.; Romero-Romero, E.; Ronquest, M.C.; Schubert, A.G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K.J.; Snyder, N.; Suriano, A.M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J.E.; Varner, R.L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B.R.; Wilkerson, J.F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A.R.; Yu, C.-H.; Yumatov, V.

    2015-01-01

    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of 76Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its subkeV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surface event contamination when searching for a WIMP signal.

  20. A dark matter search with MALBEK

    SciTech Connect (OSTI)

    Giovanetti, G. K. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Abgrall, N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aguayo, E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Avignone, III, F. T. [Univ. of South Carolina, Columbia, SC (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Barabash, A. S. [Institute for Theoretical and Experimental Physics, Moscow (Russia); Bertrand, F. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boswell, M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brudanin, V. [Joint Institute for Nuclear Research, Dubna (Russia); Busch, M. [Duke Univ., Durham, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Byram, D. [Univ. of South Dakota, Vermillion, SD (United States); Caldwell, A. S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Chan, Y. -D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Christofferson, C. D. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Combs, D. C. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Cuesta, C. [Univ. of Washington, Seattle, WA (United States); Detwiler, J. A. [Univ. of Washington, Seattle, WA (United States); Doe, P. J. [Univ. of Washington, Seattle, WA (United States); Efremenko, Yu. [Univ. of Tennessee, Knoxville, TN (United States); Egorov, V. [Joint Institute for Nuclear Research, Dubna (Russia); Ejiri, H. [Osaka Univ., Osaka (Japan); Elliott, S. R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fast, J. E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Finnerty, P. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Fraenkle, F. M. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goett, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gruszko, J. [Univ. of Washington, Seattle, WA (United States); Guiseppe, V. E. [Univ. of South Carolina, Columbia, SC (United States); Gusev, K. [Joint Institute for Nuclear Research, Dubna (Russia); Hallin, A. L. [Univ. of Alberta, Edmonton, AB (Canada); Hazama, R. [Osaka Univ., Osaka (Japan); Hegai, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tuebingen Univ., Tuebingen (Germany); Henning, R. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Hoppe, E. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Howard, S. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Howe, M. A. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Keeter, K. J. [Black Hills State Univ., Spearfish, SD (United States); Kidd, M. F. [Tennessee Tech Univ., Cookeville, TN (United States); Kochetov, O. [Joint Institute for Nuclear Research, Dubna (Russia); Konovalov, S. I. [Institute for Theoretical and Experimental Physics, Moscow (Russia); Kouzes, R. T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); LaFerriere, B. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leon, J. [Univ. of Washington, Seattle, WA (United States); Leviner, L. E. [North Carolina State Univ., Raleigh, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); Loach, J. C. [Shanghai Jiao Tong Univ., Shanghai (China); MacMullin, J. [Univ. of North Carolina, Chapel Hill, NC (United States); Triangle Univ. Nuclear Lab., Durham, NC (United States); MacMullin, S. [Univ. of North Carolina, Chapel Hill, NC (United States)

    2015-01-01

    The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of ??Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is sensitive to potential non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and explore the impact of slow surface event contamination when searching for a WIMP signal.

  1. Dark Matter Benchmark Models for Early LHC Run-2 Searches: Report of the ATLAS/CMS Dark Matter Forum

    E-Print Network [OSTI]

    Daniel Abercrombie; Nural Akchurin; Ece Akilli; Juan Alcaraz Maestre; Brandon Allen; Barbara Alvarez Gonzalez; Jeremy Andrea; Alexandre Arbey; Georges Azuelos; Patrizia Azzi; Mihailo Backovi?; Yang Bai; Swagato Banerjee; James Beacham; Alexander Belyaev; Antonio Boveia; Amelia Jean Brennan; Oliver Buchmueller; Matthew R. Buckley; Giorgio Busoni; Michael Buttignol; Giacomo Cacciapaglia; Regina Caputo; Linda Carpenter; Nuno Filipe Castro; Guillelmo Gomez Ceballos; Yangyang Cheng; John Paul Chou; Arely Cortes Gonzalez; Chris Cowden; Francesco D'Eramo; Annapaola De Cosa; Michele De Gruttola; Albert De Roeck; Andrea De Simone; Aldo Deandrea; Zeynep Demiragli; Anthony DiFranzo; Caterina Doglioni; Tristan du Pree; Robin Erbacher; Johannes Erdmann; Cora Fischer; Henning Flaecher; Patrick J. Fox; Benjamin Fuks; Marie-Helene Genest; Bhawna Gomber; Andreas Goudelis; Johanna Gramling; John Gunion; Kristian Hahn; Ulrich Haisch; Roni Harnik; Philip C. Harris; Kerstin Hoepfner; Siew Yan Hoh; Dylan George Hsu; Shih-Chieh Hsu; Yutaro Iiyama; Valerio Ippolito; Thomas Jacques; Xiangyang Ju; Felix Kahlhoefer; Alexis Kalogeropoulos; Laser Seymour Kaplan; Lashkar Kashif; Valentin V. Khoze; Raman Khurana; Khristian Kotov; Dmytro Kovalskyi; Suchita Kulkarni; Shuichi Kunori; Viktor Kutzner; Hyun Min Lee; Sung-Won Lee; Seng Pei Liew; Tongyan Lin; Steven Lowette; Romain Madar; Sarah Malik; Fabio Maltoni; Mario Martinez Perez; Olivier Mattelaer; Kentarou Mawatari; Christopher McCabe; Théo Megy; Enrico Morgante; Stephen Mrenna; Siddharth M. Narayanan; Andy Nelson; Sérgio F. Novaes; Klaas Ole Padeken; Priscilla Pani; Michele Papucci; Manfred Paulini; Christoph Paus; Jacopo Pazzini; Björn Penning; Michael E. Peskin; Deborah Pinna; Massimiliano Procura; Shamona F. Qazi; Davide Racco; Emanuele Re; Antonio Riotto; Thomas G. Rizzo; Rainer Roehrig; David Salek; Arturo Sanchez Pineda; Subir Sarkar; Alexander Schmidt; Steven Randolph Schramm; William Shepherd; Gurpreet Singh; Livia Soffi; Norraphat Srimanobhas; Kevin Sung; Tim M. P. Tait; Timothee Theveneaux-Pelzer; Marc Thomas; Mia Tosi; Daniele Trocino; Sonaina Undleeb; Alessandro Vichi; Fuquan Wang; Lian-Tao Wang; Ren-Jie Wang; Nikola Whallon; Steven Worm; Mengqing Wu; Sau Lan Wu; Hongtao Yang; Yong Yang; Shin-Shan Yu; Bryan Zaldivar; Marco Zanetti; Zhiqing Zhang; Alberto Zucchetta

    2015-07-03

    This document is the final report of the ATLAS-CMS Dark Matter Forum, a forum organized by the ATLAS and CMS collaborations with the participation of experts on theories of Dark Matter, to select a minimal basis set of dark matter simplified models that should support the design of the early LHC Run-2 searches. A prioritized, compact set of benchmark models is proposed, accompanied by studies of the parameter space of these models and a repository of generator implementations. This report also addresses how to apply the Effective Field Theory formalism for collider searches and present the results of such interpretations.

  2. Radon-related backgrounds in the LUX dark matter search

    SciTech Connect (OSTI)

    Bradley, A. [Case Western Reserve Univ., Cleveland, OH (United States); Akerib, D. S. [Case Western Reserve Univ., Cleveland, OH (United States); Araújo, H. M. [Imperial College London, London (United Kingdom); Bai, X. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Bailey, A. J. [Imperial College London, London (United Kingdom); Balajthy, J. [Univ. of Maryland, College Park, MD (United States); Bernard, E. [Yale Univ., New Haven, CT (United States); Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Byram, D. [Univ. of South Dakota, Vermillion, SD (United States); Cahn, S. B. [Yale Univ., New Haven, CT (United States); Carmona-Benitez, M. C. [Univ. of California Santa Barbara, Santa Barbara, CA (United States); Chan, C. [Brown Univ., Providence, RI (United States); Chapman, J. J. [Brown Univ., Providence, RI (United States); Chiller, A. A. [Univ. of South Dakota, Vermillion, SD (United States); Chiller, C. [Univ. of South Dakota, Vermillion, SD (United States); Coffey, T. [Case Western Reserve Univ., Cleveland, OH (United States); Currie, A. [Imperial College London, London (United Kingdom); de Viveiros, L. [Univ. of Coimbra, Coimbra (Portugal); Dobi, A. [Univ. of Maryland, College Park, MD (United States); Dobson, J. [Univ. of Edingburg, Edinburg (United Kingdom); Druszkiewicz, E. [Univ. of Rochester, Rochester, NY (United States); Edwards, B. [Yale Univ., New Haven, CT (United States); Faham, C. H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fiorucci, S. [Brown Univ., Providence, RI (United States); Flores, C. [Univ. of California, Davis, Davis, CA (United States); Gaitskell, R. J. [Brown Univ., Providence, RI (United States); Gehman, V. M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ghag, C. [Univ. College London, London (United Kingdom); Gibson, K. R. [Case Western Reserve Univ., Cleveland, OH (United States); Gilchriese, M. G.D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hall, C. [Univ. of Maryland, College Park, MD (United States); Hertel, S. A. [Yale Univ., New Haven, CT (United States); Horn, M. [Yale Univ., New Haven, CT (United States); Huang, D. Q. [Brown Univ., Providence, RI (United States); Ihm, M. [Univ. of California Berkeley, Berkeley, CA (United States); Jacobsen, R. G. [Univ. of California Berkeley, Berkeley, CA (United States); Kazkaz, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Knoche, R. [Univ. of Maryland, College Park, MD (United States); Larsen, N. A. [Yale Univ., New Haven, CT (United States); Lee, C. [Case Western Reserve Univ., Cleveland, OH (United States); Lindote, A. [Univ. of Coimbra, Coimbra (Portugal); Lopes, M. I. [Univ. of Coimbra, Coimbra (Portugal); Malling, D. C. [Brown Univ., Providence, RI (United States); Mannino, R. [Texas A & M Univ., College Station, TX (United States); McKinsey, D. N. [Yale Univ., New Haven, CT (United States); Mei, D. -M. [Univ. of South Dakota, Vermillion, SD (United States); Mock, J. [Univ. of California, Davis, Davis, CA (United States); Moongweluwan, M. [Univ. of Rochester, Rochester, NY (United States); Morad, J. [Univ. of California, Davis, Davis, CA (United States); Murphy, A. St.J. [Univ. of Edingburg, Edinburg (United Kingdom); Nehrkorn, C. [Univ. of California Santa Barbara, Santa Barbara, CA (United States); Nelson, H. [Univ. of California Santa Barbara, Santa Barbara, CA (United States); Neves, F. [Univ. of Coimbra, Coimbra (Portugal); Ott, R. A. [Univ. of California, Davis, Davis, CA (United States); Pangilinan, M. [Brown Univ., Providence, RI (United States); Parker, P. D. [Yale Univ., New Haven, CT (United States); Pease, E. K. [Yale Univ., New Haven, CT (United States); Pech, K. [Case Western Reserve Univ., Cleveland, OH (United States); Phelps, P. [Case Western Reserve Univ., Cleveland, OH (United States); Reichhart, L. [Univ. College London, London (United Kingdom); Shutt, T. [Case Western Reserve Univ., Cleveland, OH (United States); Silva, C. [Univ. of Coimbra, Coimbra (Portugal)

    2015-01-01

    The LUX detector is currently in operation at the Davis Campus at the 4850’ level of the Sanford Underground Research Facility (SURF) in Lead, SD to directly search for WIMP dark matter. Knowing the type and rate of backgrounds is critical in a rare, low energy event search, and LUX was designed, constructed, and deployed to mitigate backgrounds, both internal and external. An important internal background are decays of radon and its daughters. These consist of alpha decays, which are easily tagged and are a tracer of certain backgrounds, and beta decays, some of which are not as readily tagged and present a background for the WIMP search. We report on studies of alpha decay and discuss implications for the WIMP search.

  3. Radon-related backgrounds in the LUX dark matter search

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bradley, A.; Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Bernard, E.; Bernstein, A.; Byram, D.; Cahn, S. B.; et al

    2015-01-01

    The LUX detector is currently in operation at the Davis Campus at the 4850’ level of the Sanford Underground Research Facility (SURF) in Lead, SD to directly search for WIMP dark matter. Knowing the type and rate of backgrounds is critical in a rare, low energy event search, and LUX was designed, constructed, and deployed to mitigate backgrounds, both internal and external. An important internal background are decays of radon and its daughters. These consist of alpha decays, which are easily tagged and are a tracer of certain backgrounds, and beta decays, some of which are not as readily taggedmore »and present a background for the WIMP search. We report on studies of alpha decay and discuss implications for the WIMP search.« less

  4. Direct Dark Matter Searches with CDMS and XENON

    E-Print Network [OSTI]

    Kaixuan Ni; Laura Baudis

    2006-11-09

    The Cryogenic Dark Matter Search (CDMS) and XENON experiments aim to directly detect dark matter in the form of weakly interacting massive particles (WIMPs) via their elastic scattering on the target nuclei. The experiments use different techniques to suppress background event rates to the minimum, and at the same time, to achieve a high WIMP detection rate. The operation of cryogenic Ge and Si crystals of the CDMS-II experiment in the Soudan mine yielded the most stringent spin-independent WIMP-nucleon cross-section (~10^{-43} cm^2) at a WIMP mass of 60 GeV/c^2. The two-phase xenon detector of the XENON10 experiment is currently taking data in the Gran Sasso underground lab and promising preliminary results were recently reported. Both experiments are expected to increase their WIMP sensitivity by a one order of magnitude in the scheduled science runs for 2007.

  5. The Cold Dark Matter Search test stand warm electronics card

    SciTech Connect (OSTI)

    Hines, Bruce; Hansen, Sten; Huber, Martin; Kiper, Terry; Rau, Wolfgang; Saab, Tarek; Seitz, Dennis; Sundqvist, Kyle; Mandic, Vuk; /Minnesota U.

    2010-11-01

    A card which does the signal processing for four SQUID amplifiers and two charge sensitive channels is described. The card performs the same functions as is presently done with two custom 9U x 280mm Eurocard modules, a commercial multi-channel VME digitizer, a PCI to GPIB interface, a PCI to VME interface and a custom built linear power supply. By integrating these functions onto a single card and using the power over Ethernet standard, the infrastructure requirements for instrumenting a Cold Dark Matter Search (CDMS) detector test stand are significantly reduced.

  6. Dark matter production from Goldstone boson interactions and implications for direct searches and dark radiation

    SciTech Connect (OSTI)

    Garcia-Cely, Camilo; Ibarra, Alejandro; Molinaro, Emiliano E-mail: alejandro.ibarra@ph.tum.de

    2013-11-01

    The stability of the dark matter particle could be attributed to the remnant Z{sub 2} symmetry that arises from the spontaneous breaking of a global U(1) symmetry. This plausible scenario contains a Goldstone boson which, as recently shown by Weinberg, is a strong candidate for dark radiation. We show in this paper that this Goldstone boson, together with the CP-even scalar associated to the spontaneous breaking of the global U(1) symmetry, plays a central role in the dark matter production. Besides, the mixing of the CP-even scalar with the Standard Model Higgs boson leads to novel Higgs decay channels and to interactions with nucleons, thus opening the possibility of probing this scenario at the LHC and in direct dark matter search experiments. We carefully analyze the latter possibility and we show that there are good prospects to observe a signal at the future experiments LUX and XENON1T provided the dark matter particle was produced thermally and has a mass larger than ? 25 GeV.

  7. Dark matter production from Goldstone boson interactions and implications for direct searches and dark radiation

    E-Print Network [OSTI]

    Camilo Garcia-Cely; Alejandro Ibarra; Emiliano Molinaro

    2013-11-07

    The stability of the dark matter particle could be attributed to the remnant $Z_2$ symmetry that arises from the spontaneous breaking of a global U(1) symmetry. This plausible scenario contains a Goldstone boson which, as recently shown by Weinberg, is a strong candidate for dark radiation. We show in this paper that this Goldstone boson, together with the CP-even scalar associated to the spontaneous breaking of the global U(1) symmetry, plays a central role in the dark matter production. Besides, the mixing of the CP-even scalar with the Standard Model Higgs boson leads to novel Higgs decay channels and to interactions with nucleons, thus opening the possibility of probing this scenario at the LHC and in direct dark matter search experiments. We carefully analyze the latter possibility and we show that there are good prospects to observe a signal at the future experiments LUX and XENON1T provided the dark matter particle was produced thermally and has a mass larger than ~25 GeV.

  8. The darkside multiton detector for the direct dark matter search

    SciTech Connect (OSTI)

    Aalseth, C. E.; Agnes, P.; Alton, A.; Arisaka, K.; Asner, D. M.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Brigatti, A.; Brodsky, J.; Budano, F.; Cadonati, L.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Cavalcante, P.; Chepurnov, A.; Cocco, A. G.; Condon, C.; Crippa, L.; D’Angelo, D.; D’Incecco, M.; Davini, S.; De Deo, M.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Forster, G.; Foxe, M.; Franco, D.; Gabriele, F.; Galbiati, C.; Goretti, A.; Grandi, L.; Gromov, M.; Guan, M. Y.; Guardincerri, Y.; Hackett, B.; Herner, K.; Hime, A.; Humble, P.; Hungerford, E.; Ianni, Al.; Ianni, An.; Jaffe, D. E.; Jollet, C.; Keeter, K.; Kendziora, C.; Kidner, S.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kurlej, A.; Li, P. X.; Lissia, M.; Lombardi, P.; Ludhova, L.; Luitz, S.; Lukyachenko, G.; Ma, Y. Q.; Machulin, I.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Markov, D.; Martoff, J.; Meregaglia, A.; Meroni, E.; Meyers, P. D.; Miletic, T.; Milincic, R.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B.; Muratova, V.; Musico, P.; Montanari, D.; Nelson, A.; Odrowski, S.; Odrzywolek, A.; Orrell, J. L.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Parsells, B.; Pelczar, K.; Pelliccia, N.; Perasso, S.; Perasso, L.; Pocar, A.; Pordes, S.; Pugachev, D.; Qian, H.; Randle, K.; Ranucci, G.; Razeto, A.; Recine, K.; Reinhold, B.; Renshaw, A.; Romani, A.; Rossi, N.; Rossi, B.; Rountree, S. D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Sangiorgio, S.; Segreto, E.; Semenov, D.; Shields, E.; Skorokhvatov, M.; Smallcomb, M.; Smirnov, O.; Sotnikov, A.; Suvurov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Unzhakov, E.; Vogelaar, R. B.; Wada, M.; Walker, S. E.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Williams, R.; Wojcik, M.; Xu, J.; Yang, C. G.; Yoo, J.; Yu, B.; Zavatarelli, S.; Zhong, W. L.; Zuzel, G.

    2015-01-01

    Although the existence of dark matter is supported by many evidences, based on astrophysical measurements, its nature is still completely unknown. One major candidate is represented by weakly interacting massive particles (WIMPs), which could in principle be detected through their collisions with ordinary nuclei in a sensitive target, producing observable low-energy (<100 keV) nuclear recoils. The DarkSide program aims at the WIPMs detection using a liquid argon time projection chamber (LAr-TPC). In this paper we quickly review the DarkSide program focusing in particular on the next generation experiment DarkSide-G2, a 3.6-ton LAr-TPC. The different detector components are described as well as the improvements needed to scale the detector from DarkSide-50 (50 kg LAr-TPC) up to DarkSide-G2. Finally, the preliminary results on background suppression and expected sensitivity are presented.

  9. The AMS-02 Transition Radiation Detector to Search for Dark Matter in Space

    E-Print Network [OSTI]

    Roma "La Sapienza", Università di

    The AMS-02 Transition Radiation Detector to Search for Dark Matter in Space Francesca Bucci) to measure the primary cosmic rays spectrum in space. A Transition Radiation Detector (TRD) will provide in the energy range of interest. Index Terms-- Transition radiation detector, straw tubes, gas gain, dark matter

  10. The darkside multiton detector for the direct dark matter search

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aalseth, C. E.; Agnes, P.; Alton, A.; Arisaka, K.; Asner, D. M.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; et al

    2015-01-01

    Although the existence of dark matter is supported by many evidences, based on astrophysical measurements, its nature is still completely unknown. One major candidate is represented by weakly interacting massive particles (WIMPs), which could in principle be detected through their collisions with ordinary nuclei in a sensitive target, producing observable low-energy (more »as the improvements needed to scale the detector from DarkSide-50 (50 kg LAr-TPC) up to DarkSide-G2. Finally, the preliminary results on background suppression and expected sensitivity are presented.« less

  11. pMSSM Dark Matter Searches on Ice

    SciTech Connect (OSTI)

    Cotta, R.C.; /SLAC; Howe, K.T.K.; /SLAC /Stanford U., Phys. Dept.; Hewett, J.L.; Rizzo, T.G.; /SLAC

    2011-08-12

    We explore the capability of the IceCube/Deepcore array to discover signal neutrinos resulting from the annihilations of Supersymmetric WIMPS that may be captured in the solar core. In this analysis, we use a previously generated set of {approx} 70k model points in the 19-dimensional parameter space of the pMSSM which satisfy existing experimental and theoretical constraints. Our calculations employ a realistic estimate of the IceCube/DeepCore effective area that has been modeled by the IceCube collaboration. We find that a large fraction of the pMSSM models are shown to have significant signal rates in the anticipated IceCube/DeepCore 1825 day dataset, including some prospects for an early discovery. Many models where the LSP only constitutes a small fraction of the total dark matter relic density are found to have observable rates. We investigate in detail the dependence of the signal neutrino fluxes on the LSP mass, weak eigenstate composition, annihilation products and thermal relic density, as well as on the spin-independent and spin-dependent scattering cross sections. Lastly, We compare the model coverage of IceCube/DeepCore to that obtainable in near-future direct detection experiments and to pMSSM searches at the 7 TeV LHC.

  12. Carbon Nanotubes Potentialities in Directional Dark Matter Searches

    E-Print Network [OSTI]

    L. M. Capparelli; G. Cavoto; D. Mazzilli; A. D. Polosa

    2014-12-28

    We propose a new solution to the problem of dark matter directional detection based on large parallel arrays of carbon nanotubes. The phenomenon of ion channeling in single wall nanotubes is simulated to calculate the expected number of recoiling carbon ions, due to the hypothetical scattering with dark matter particles, subsequently being driven along their longitudinal extension. As shown by explicit calculation, the relative orientation of the carbon nanotube array with respect to the direction of motion of the Sun has an appreciable effect on the channeling probability of the struck ion and this provides the required detector anisotropic response.

  13. Low radioactivity argon dark matter search results from the DarkSide-50 experiment

    E-Print Network [OSTI]

    Agnes, P; Albuquerque, I F M; Alexander, T; Alton, A K; Arisaka, K; Back, H O; Baldin, B; Biery, K; Bonfini, G; Bossa, M; Bottino, B; Brigatti, A; Brodsky, J; Budano, F; Bussino, S; Cadeddu, M; Cadonati, L; Cadoni, M; Calaprice, F; Canci, N; Candela, A; Cao, H; Cariello, M; Carlini, M; Catalanotti, S; Cavalcante, P; Chepurnov, A; Cocco, A G; Covone, G; Crippa, L; D'Angelo, D; D'Incecco, M; Davini, S; De Cecco, S; De Deo, M; De Vincenzi, M; Derbin, A; Devoto, 25 A; Di Eusanio, F; Di Pietro, G; Edkins, E; Empl, A; Fan, A; Fiorillo, G; Fomenko, K; Forster, G; Franco, D; Gabriele, F; Galbiati, C; Giganti, C; Goretti, A M; Granato, F; Grandi, L; Gromov, M; Guan, M; Guardincerri, Y; Hackett, B R; Herner, K; Hungerford, E V; Ianni, Al; Ianni, An; James, I; Jollet, C; Keeter, K; Kendziora, C L; Kobychev, V; Koh, G; Korablev, D; Korga, G; Kubankin, A; Li, X; Lissia, M; Lombardi, P; Luitz, S; Ma, Y; Machulin, I N; Mandarano, A; Mari, S M; Maricic, J; Marini, L; Martoff, C J; Meregaglia, A; Meyers, P D; Miletic, T; Milincic, R; Montanari, D; Monte, A; Montuschi, M; Monzani, M; Mosteiro, P; Mount, B J; Muratova, V N; Musico, P; Napolitano, J; Nelson, A; Odrowski, S; Orsini, M; Ortica, F; Pagani, L; Pallavicini, M; Pantic, E; Parmeggiano, S; Pelczar, K; Pelliccia, N; Perasso, S; Pocar, A; Pordes, S; Pugachev, D A; Qian, H; Randle, K; Ranucci, G; Razeto, A; Reinhold, B; Renshaw, A L; Romani, A; Rossi, B; Rossi, N; Rountree, D; Sablone, D; Saggese, P; Saldanha, R; Sands, W; Sangiorgio, S; Savarese, C; Segreto, E; Semenov, D A; Shields, E; Singh, P N; Skorokhvatov, M D; Smallcomb, M; Smirnov, O; Sotnikov, A; Stanford, C; Suvorov, Y; Tartaglia, R; Tatarowicz, J; Testera, G; Tonazzo, A; Trinchese, P; Unzhakov, E V; Vishneva, A; Vogelaar, B; Wada, M; Walker, S; Wang, H; Wang, Y; Watson, A W; Westerdale, S; Wilhelmi, J; Wojcik, M M; Xiang, X; Xu, J; Yang, C; Yoo, J; Zavatarelli, S; Zec, A; Zhong, W; Zhu, C; Zuzel, G

    2015-01-01

    The DarkSide-50 dark matter search reports the first results obtained using a target of low-radioactivity argon extracted from underground sources. The experiment is located at the Laboratori Nazionali del Gran Sasso and uses a two-phase time projection chamber as a detector. A total of 155 kg of low radioactivity argon has been obtained, and we have determined that underground argon is depleted in Ar-39 by a factor (1.4 +- 0.2) x 10^3 relative to atmospheric argon. The underground argon was also found to contain (2.05 +- 0.13) mBq/kg of Kr-85. We found no evidence for dark matter in the form of WIMPs in 70.9 live-days of data with a fiducial mass of (36.9 +- 0.6) kg. When combined with our preceding search with an atmospheric argon target, we set a 90 % C.L. upper limit on the WIMP-nucleon spin-independent cross section of 2.0 x 10^-44 cm^2 (8.6 x 10^-44 cm^2, 8.0 x 10^-43 cm^2 ) for a WIMP mass of 100 GeV/c^2 (1 TeV/c^2 , 10 TeV/c^2 ).

  14. Demonstration of surface electron rejection with interleaved germanium detectors for dark matter searches

    E-Print Network [OSTI]

    Anderson, Adam Jonathan

    The SuperCDMS experiment in the Soudan Underground Laboratory searches for dark matter with a 9-kg array of cryogenic germanium detectors. Symmetric sensors on opposite sides measure both charge and phonons from each ...

  15. Quantifying galactic propagation uncertainty in WIMP dark matter search with AMS01 Z=-1 spectrum

    E-Print Network [OSTI]

    Xiao, Sa, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    A search for a WIMP dark matter annihilation signal is carried out in the AMS01 negatively charged (Z=-I) particle spectrum, following a set of supersymmetric benchmark scenarios in the mSUGRA framework. The result is ...

  16. Dark Matters

    ScienceCinema (OSTI)

    Joseph Silk

    2010-01-08

    One of the greatest mysteries in the cosmos is that it is mostly dark.  Astronomers and particle physicists today are seeking to unravel the nature of this mysterious, but pervasive dark matter which has profoundly influenced the formation of structure in the universe.  I will describe the complex interplay between galaxy formation and dark matter detectability and review recent attempts to measure particle dark matter by direct and indirect means.

  17. ZEPLIN-III direct dark matter search : final results and measurements in support of next generation instruments 

    E-Print Network [OSTI]

    Reichhart, Lea

    2013-11-28

    Astrophysical observations give convincing evidence for a vast non-baryonic component, the so-called dark matter, accounting for over 20% of the overall content of our Universe. Direct dark matter search experiments ...

  18. Nuclear spin structure in dark matter search: The finite momentum transfer limit

    E-Print Network [OSTI]

    V. A. Bednyakov; F. Simkovic

    2006-08-09

    Spin-dependent elastic scattering of weakly interacting massive dark matter particles (WIMP) off nuclei is reviewed. All available, within different nuclear models, structure functions S(q) for finite momentum transfer (q>0) are presented. These functions describe the recoil energy dependence of the differential event rate due to the spin-dependent WIMP-nucleon interactions. This paper, together with the previous paper ``Nuclear spin structure in dark matter search: The zero momentum transfer limit'', completes our review of the nuclear spin structure calculations involved in the problem of direct dark matter search.

  19. The Electronics and Data Acquisition System of the DarkSide Dark Matter Search

    E-Print Network [OSTI]

    Alexander, T; Arisaka, K; Back, H O; Baldin, B; Biery, K; Bonfini, G; Bossa, M; Brigatti, A; Brodsky, J; Budano, F; Cadonati, L; Calaprice, F; Canci, N; Candela, A; Cao, H; Cariello, M; Cavalcante, P; Chavarria, A; Chepurnov, A; Cocco, A G; Crippa, L; D'Angelo, D; D'Incecco, M; Davini, S; De Deo, M; Derbin, A; Devoto, A; Di Eusanio, F; Di Pieto, G; Edkins, E; Empl, A; Fan, A; Fiorillo, G; Fomenko, K; Forster, G; Franco, D; Gabriele, F; Galbiati, C; Goretti, A; Grandi, L; Gromov, M; Guan, M Y; Guardincerri, Y; Hackett, B; Herner, K; Hungerford, E; Ianni, Al; Ianni, An; Jollet, C; Keeter, K; Kendziora, C; Kidner, S; Kobychev, V; Koh, G; Korablev, D; Korga, G; Kurlej, A; Li, P X; Loer, B; Lombardi, P; Love, C; Ludhova, L; Luitz, S; Ma, Y Q; Machulin, I; Mandarano, A; Mari, S M; Maricic, J; Marini, L; Martoff, J; Meregaglia, A; Meroni, E; Meyers, P D; Milincic, R; Montanari, D; Montuschi, M; Monzani, M E; Mosteiro, P; Mount, B; Muratova, V; Musico, P; Nelson, A; Odrowski, S; Okounkoa, M; Orsini, M; Ortica, F; Pagani, L; Pallavicini, M; Pantic, E; Papp, L; Parmeggiano, S; Parsells, Bob; Pelczar, K; Pelliccia, N; Perasso, S; Pocar, A; Pordes, S; Pugachev, D; Qian, H; Randle, K; Ranucci, G; Razeto, A; Reinhold, B; Renshaw, A; Romani, A; Rossi, B; Rossi, N; Rountree, S D; Sablone, D; Saggese, P; Saldanha, R; Sands, W; Sangiorgio, S; Segreto, E; Semenov, D; Shields, E; Skorokhvatov, M; Smirnov, O; Sotnikov, A; Stanford, C; Suvorov,; Tartaglia, R; Tatarowicz, J; Testera, G; Tonazzo, A; Unzhakov, E; Vogelaar, R B; Wada, M; Walker, S E; Wang, H; Wang, Y; Watson, A; Westerdale, S; Wojcik, M; Wright, A; Xiang, X; Xu, J; Yang, C G; Yoo, J; Zavatarelli, S; Zec, A; Zhu, C; Zuzel, G

    2014-01-01

    It is generally inferred from astronomical measurements that Dark Matter (DM) comprises approximately 27\\% of the energy-density of the universe. If DM is a subatomic particle, a possible candidate is a Weakly Interacting Massive Particle (WIMP), and the DarkSide-50 (DS) experiment is a direct search for evidence of WIMP-nuclear collisions. DS is located underground at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy, and consists of three active, embedded components; an outer water veto (CTF), a liquid scintillator veto (LSV), and a liquid argon (LAr) time projection chamber (TPC). This paper describes the data acquisition and electronic systems of the DS detectors, designed to detect the residual ionization from such collisions.

  20. Dark Matter Annihilation and Decay Searches with the High Altitude Water Cherenkov (HAWC) Observatory

    E-Print Network [OSTI]

    Harding, J Patrick

    2015-01-01

    In order to observe annihilation and decay of dark matter, several types of potential sources should be considered. Some sources, such as dwarf galaxies, are expected to have very low astrophysical backgrounds but fairly small dark matter densities. Other sources, like the Galactic center, are expected to have larger densities of dark matter but also have more complicated backgrounds from other astrophysical sources. To search for signatures of dark matter, the large field-of-view of the HAWC detector, covering 2 sr at a time, especially enables searches from sources of dark matter annihilation and decay, which are extended over several degrees on the sky. With a sensitivity over 2/3 of the sky, HAWC has the ability to probe a large fraction of the sky for the signals of TeV-mass dark matter. In particular, HAWC should be the most sensitive experiment to signals coming from dark matter with masses greater than 10-100 TeV. We present the HAWC sensitivity to annihilating and decaying dark matter signals for sev...

  1. Dark Matter Annihilation and Decay Searches with the High Altitude Water Cherenkov (HAWC) Observatory

    E-Print Network [OSTI]

    J. Patrick Harding; Brenda Dingus; for the HAWC Collaboration

    2015-08-18

    In order to observe annihilation and decay of dark matter, several types of potential sources should be considered. Some sources, such as dwarf galaxies, are expected to have very low astrophysical backgrounds but fairly small dark matter densities. Other sources, like the Galactic center, are expected to have larger densities of dark matter but also have more complicated backgrounds from other astrophysical sources. To search for signatures of dark matter, the large field-of-view of the HAWC detector, covering 2 sr at a time, especially enables searches from sources of dark matter annihilation and decay, which are extended over several degrees on the sky. With a sensitivity over 2/3 of the sky, HAWC has the ability to probe a large fraction of the sky for the signals of TeV-mass dark matter. In particular, HAWC should be the most sensitive experiment to signals coming from dark matter with masses greater than 10-100 TeV. We present the HAWC sensitivity to annihilating and decaying dark matter signals for several likely sources of these signals.

  2. Aldo Morselli, INFN Roma Tor Vergata 1 Search for Dark Matter in the Sky

    E-Print Network [OSTI]

    Morselli, Aldo

    Aldo Morselli, INFN Roma Tor Vergata 1 Search for Dark Matter in the Sky Aldo Morselli INFN Roma Tor Vergata 14 Jun 2012 Dark Side of the Univers 2012 Buzios 10-15 June #12;Aldo Morselli, INFN Roma press/web releases. #12;Aldo Morselli, INFN Roma Tor Vergata 10 The Fermi LAT gamma-ray sky 3-year all

  3. Direct dark matter searches—Test of the Big Bounce Cosmology

    SciTech Connect (OSTI)

    Cheung, Yeuk-Kwan E.; Vergados, J.D. E-mail: vergados@uoi.gr

    2015-02-01

    We consider the possibility of using dark matter particle's mass and its interaction cross section as a smoking gun signal of the existence of a Big Bounce at the early stage in the evolution of our currently observed universe. A study of dark matter production in the pre-bounce contraction and the post bounce expansion epochs of this universe reveals a new venue for achieving the observed relic abundance of our present universe. Specifically, it predicts a characteristic relation governing a dark matter mass and interaction cross section and a factor of 1/2 in thermally averaged cross section, as compared to the non-thermal production in standard cosmology, is needed for creating enough dark matter particle to satisfy the currently observed relic abundance because dark matter is being created during the pre-bounce contraction, in addition to the post-bounce expansion. As the production rate is lower than the Hubble expansion rate information of the bounce universe evolution is preserved. Therefore once the value of dark matter mass and interaction cross section are obtained by direct detection in laboratories, this alternative route becomes a signature prediction of the bounce universe scenario. This leads us to consider a scalar dark matter candidate, which if it is light, has important implications on dark matter searches.

  4. Interplay and Characterization of Dark Matter Searches at Colliders and in Direct Detection Experiments

    E-Print Network [OSTI]

    Sarah A. Malik; Christopher McCabe; Henrique Araujo; Alexander Belyaev; Celine Boehm; Jim Brooke; Oliver Buchmueller; Gavin Davies; Albert De Roeck; Kees de Vries; Matthew J. Dolan; John Ellis; Malcolm Fairbairn; Henning Flaecher; Loukas Gouskos; Valentin V. Khoze; Greg Landsberg; Dave Newbold; Michele Papucci; Timothy Sumner; Marc Thomas; Steven Worm

    2014-09-23

    In this White Paper we present and discuss a concrete proposal for the consistent interpretation of Dark Matter searches at colliders and in direct detection experiments. Based on a specific implementation of simplified models of vector and axial-vector mediator exchanges, this proposal demonstrates how the two search strategies can be compared on an equal footing.

  5. Dark Matter Searches for Monoenergetic Neutrinos Arising from Stopped Meson Decay in the Sun

    E-Print Network [OSTI]

    Carsten Rott; Seongjin In; Jason Kumar; David Yaylali

    2015-10-01

    Dark matter can be gravitationally captured by the Sun after scattering off solar nuclei. Annihilations of the dark matter trapped and accumulated in the centre of the Sun could result in one of the most detectable and recognizable signals for dark matter. Searches for high-energy neutrinos produced in the decay of annihilation products have yielded extremely competitive constraints on the spin-dependent scattering cross sections of dark matter with nuclei. Recently, the low energy neutrino signal arising from dark-matter annihilation to quarks which then hadronize and shower has been suggested as a competitive and complementary search strategy. These high-multiplicity hadronic showers give rise to a large amount of pions which will come to rest in the Sun and decay, leading to a unique sub-GeV neutrino signal. We here improve on previous works by considering the monoenergetic neutrino signal arising from both pion and kaon decay. We consider searches at liquid scintillation, liquid argon, and water Cherenkov detectors and find very competitive sensitivities for few-GeV dark matter masses.

  6. The leptophilic dark matter with $Z'$ interaction: from indirect searches to future $e^+ e^-$ collider searches

    E-Print Network [OSTI]

    Chen, Ning; Wang, Xiao-Ping

    2015-01-01

    We investigate the scenario where the dark matter only interacts with the charged leptons in the standard model via a neutral vector mediator $Z'$. Such a scenario with a 430 GeV dark matter can fit the recent positron fluxes observed by the AMS-02 Collaborations, with the reasonable boost factors. We study the possibility of searching such leptophilic $Z'$ via its lepton final states and invisible decay modes at the future electron-positron colliders, such as the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). We find that for the benchmark models with $Z'$ mass from $1.0\\,\\TeV$ to $1.5\\,\\TeV$, the searches for the invisible decays of $Z'\\to \\bar \\chi \\chi$ is easily achieved at the CLIC $1.5\\,\\TeV$ runs via the mono-photon process. However, lighter $Z'$ with mass from $0.5\\,\\TeV$ to $0.8\\,\\TeV$ are challenging to see. The di-lepton plus single photon channel can reveal the $Z'$ mass at the ILC and CLIC with moderate luminosities.

  7. The leptophilic dark matter with $Z'$ interaction: from indirect searches to future $e^+ e^-$ collider searches

    E-Print Network [OSTI]

    Ning Chen; Jian Wang; Xiao-Ping Wang

    2015-02-04

    We investigate the scenario where the dark matter only interacts with the charged leptons in the standard model via a neutral vector mediator $Z'$. Such a scenario with a 430 GeV dark matter can fit the recent positron fluxes observed by the AMS-02 Collaborations, with the reasonable boost factors. We study the possibility of searching such leptophilic $Z'$ via its lepton final states and invisible decay modes at the future electron-positron colliders, such as the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). We find that for the benchmark models with $Z'$ mass from 1.0 TeV to 1.5 TeV, the searches for the invisible decays of $Z'\\to \\bar \\chi \\chi$ is easily achieved at the CLIC 1.5 TeV runs via the mono-photon process. However, lighter $Z'$ with mass from 0.5 TeV to 0.8 TeV are challenging to see. The di-lepton plus single photon channel can reveal the $Z'$ mass at the ILC and CLIC with moderate luminosities.

  8. Searching for Smoking Gun Signatures of Decaying Dark Matter

    E-Print Network [OSTI]

    Joshua T. Ruderman; Tomer Volansky

    2009-08-11

    Clear methods to differentiate between decaying and annihilating dark matter (DM) scenarios are still by and large unavailable. In this note, we study the potential astrophysical signatures of a new class of hidden sector decaying DM models, which can address the recent cosmic ray measurements. Such models may produce primary photons and/or neutrinos at large rates, correlated with the leptonic production. The photon and neutrino spectra will then contain sharp features at the TeV scale. We demonstrate the discovery potential for upcoming and future measurements by FERMI, HESS, AGIS and IceCube/DeepCore. We show that these models may be discovered in the near future. Specifically, measurements of diffuse gamma rays by FERMI can detect the start of a hard photon feature. We argue that these hard spectra can be produced by decaying dark matter and be consistent with current constraints, but are difficult to reconcile with models of annihilating DM. Consequently the measurement of a hard spectral feature, in correlation with the current cosmic ray measurements, will strongly favor decaying DM models. Finally we comment on the preliminary results from the Inner Galaxy presented by the FERMI collaboration.

  9. Indirect searches for dark matter with the Fermi large area telescopestar

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Albert, Andrea

    2015-01-01

    There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce ? rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for ?-ray spectral lines and ?-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.

  10. Indirect Searches for Dark Matter with the Fermi Large Area Telescope1

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Albert, Andrea

    2015-01-01

    There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce ? rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for ?-ray spectral lines and ?-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.

  11. Indirect searches for dark matter with the Fermi large area telescope

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Albert, Andrea

    2015-03-24

    There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce ? rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for ?-ray spectral lines and ?-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.

  12. Dark Matter Searches for Monoenergetic Neutrinos Arising from Stopped Meson Decay in the Sun

    E-Print Network [OSTI]

    Rott, Carsten; Kumar, Jason; Yaylali, David

    2015-01-01

    Dark matter can be gravitationally captured by the Sun after scattering off solar nuclei. Annihilations of the dark matter trapped and accumulated in the centre of the Sun could result in one of the most detectable and recognizable signals for dark matter. Searches for high-energy neutrinos produced in the decay of annihilation products have yielded extremely competitive constraints on the spin-dependent scattering cross sections of dark matter with nuclei. Recently, the low energy neutrino signal arising from dark-matter annihilation to quarks which then hadronize and shower has been suggested as a competitive and complementary search strategy. These high-multiplicity hadronic showers give rise to a large amount of pions which will come to rest in the Sun and decay, leading to a unique sub-GeV neutrino signal. We here improve on previous works by considering the monoenergetic neutrino signal arising from both pion and kaon decay. We consider searches at liquid scintillation, liquid argon, and water Cherenkov...

  13. Particle dark matter searches outside the Local neighborhood

    E-Print Network [OSTI]

    Regis, Marco; Cuoco, Alessandro; Branchini, Enzo; Fornengo, Nicolao; Viel, Matteo

    2015-01-01

    If dark matter (DM) is composed by particles which are non-gravitationally coupled to ordinary matter, their annihilations or decays in cosmic structures can result in detectable radiation. We show that the most powerful technique to detect a particle DM signal outside the Local Group is to study the angular cross-correlation of non-gravitational signals with low-redshift gravitational probes. This method allows to enhance signal-to-noise from the regions of the Universe where the DM-induced emission is preferentially generated. We demonstrate the power of this approach by focusing on GeV-TeV DM and on the recent cross-correlation analysis between the 2MASS galaxy catalogue and the Fermi-LAT gamma-ray maps. We show that this technique is more sensitive than other extragalactic gamma-ray probes, such as the energy spectrum and angular autocorrelation of the extragalactic background, and emission from clusters of galaxies. Intriguingly, we find that the measured cross-correlation can be well fitted by a DM comp...

  14. Thermal transport of the solar captured dark matter and its impact on the indirect dark matter search

    E-Print Network [OSTI]

    Chen, Chian-Shu; Lin, Yen-Hsun

    2015-01-01

    We study the thermal transport occurring in the system of solar captured dark matter (DM) and explore its impact on the DM indirect search signal. We particularly focus on the scenario of self-interacting DM (SIDM). The flows of energies in and out of the system are caused by solar captures via DM-nucleon and DM-DM scatterings, the energy dissipation via DM annihilation, and the heat exchange between DM and solar nuclei. We examine the DM temperature evolution and demonstrate that the DM temperature can be higher than the core temperature of the Sun if the DM-nucleon cross section is sufficiently small such that the energy flow due to DM self-interaction becomes relatively important. We argue that the correct DM temperature should be used for accurately predicting the DM annihilation rate, which is relevant to the DM indirect detection.

  15. Thermal transport of the solar captured dark matter and its impact on the indirect dark matter search

    E-Print Network [OSTI]

    Chian-Shu Chen; Guey-Lin Lin; Yen-Hsun Lin

    2015-09-01

    We study the thermal transport occurring in the system of solar captured dark matter (DM) and explore its impact on the DM indirect search signal. We particularly focus on the scenario of self-interacting DM (SIDM). The flows of energies in and out of the system are caused by solar captures via DM-nucleon and DM-DM scatterings, the energy dissipation via DM annihilation, and the heat exchange between DM and solar nuclei. We examine the DM temperature evolution and demonstrate that the DM temperature can be higher than the core temperature of the Sun if the DM-nucleon cross section is sufficiently small such that the energy flow due to DM self-interaction becomes relatively important. We argue that the correct DM temperature should be used for accurately predicting the DM annihilation rate, which is relevant to the DM indirect detection.

  16. Dark Matter 2014

    E-Print Network [OSTI]

    Marc Schumann

    2015-01-06

    This article gives an overview on the status of experimental searches for dark matter at the end of 2014. The main focus is on direct searches for weakly interacting massive particles (WIMPs) using underground-based low-background detectors, especially on the new results published in 2014. WIMPs are excellent dark matter candidates, predicted by many theories beyond the standard model of particle physics, and are expected to interact with the target nuclei either via spin-independent (scalar) or spin-dependent (axial-vector) couplings. Non-WIMP dark matter candidates, especially axions and axion-like particles are also briefly discussed.

  17. Can Solar Neutrinos be a Serious Background in Direct Dark Matter Searches?

    E-Print Network [OSTI]

    J. D. Vergados; H. Ejiri

    2008-05-30

    The coherent contribution of all neutrons in neutrino nucleus scattering due to the neutral current is examined considering the boron solar neutrinos. These neutrinos could potentially become a source of background in the future dark matter searches aiming at nucleon cross sections in the region well below the few events per ton per year.

  18. Search for ultralight scalar dark matter with atomic spectroscopy

    E-Print Network [OSTI]

    Ken Van Tilburg; Nathan Leefer; Lykourgos Bougas; Dmitry Budker

    2015-04-08

    We report new limits on ultralight scalar dark matter (DM) with dilaton-like couplings to photons that can induce oscillations in the fine-structure constant alpha. Atomic dysprosium exhibits an electronic structure with two nearly degenerate levels whose energy splitting is sensitive to changes in alpha. Spectroscopy data for two isotopes of dysprosium over a two-year span is analyzed for coherent oscillations with angular frequencies below 1 rad/s. No signal consistent with a DM coupling is identified, leading to new constraints on dilaton-like photon couplings over a wide mass range. Under the assumption that the scalar field comprises all of the DM, our limits on the coupling exceed those from equivalence-principle tests by up to 4 orders of magnitude for masses below 3 * 10^-18 eV. Excess oscillatory power, inconsistent with fine-structure variation, is detected in a control channel, and is likely due to a systematic effect. Our atomic spectroscopy limits on DM are the first of their kind, and leave substantial room for improvement with state-of-the-art atomic clocks.

  19. In Wino Veritas? Indirect Searches Shed Light on Neutralino Dark Matter

    E-Print Network [OSTI]

    JiJi Fan; Matthew Reece

    2013-07-16

    Indirect detection constraints on gamma rays (both continuum and lines) have set strong constraints on wino dark matter. By combining results from Fermi-LAT and HESS, we show that: light nonthermal wino dark matter is strongly excluded; thermal wino dark matter is allowed only if the Milky Way dark matter distribution has a significant (>~0.4 kpc) core; and for plausible NFW and Einasto distributions the entire range of wino masses from 100 GeV up to 3 TeV can be excluded. The case of light, nonthermal wino dark matter is particularly interesting in scenarios with decaying moduli that reheat the universe to a low temperature. Typically such models have been discussed for low reheating temperatures, not far above the BBN bound of a few MeV. We show that constraints on the allowed wino relic density push such models to higher reheating temperatures and hence heavier moduli. Even for a flattened halo model consisting of an NFW profile with constant-density core inside 1 kpc and a density near the sun of 0.3 GeV/cm^3, for 150 GeV winos current data constrains the reheat temperature to be above 1.4 GeV. As a result, for models in which the wino mass is a loop factor below the gravitino mass, the data favor moduli that are more than an order of magnitude heavier than the gravitino. We discuss some of the sobering implications of this result for the status of supersymmetry. We also comment on other neutralino dark matter scenarios, in particular the case of mixed bino/higgsino dark matter. We show that in this case, direct and indirect searches are complementary to each other and could potentially cover most of the parameter space.

  20. Characterising dark matter searches at colliders and direct detection experiments: Vector mediators

    SciTech Connect (OSTI)

    Buchmueller, Oliver; Dolan, Matthew J.; Malik, Sarah A.; McCabe, Christopher

    2015-01-09

    We introduce a Minimal Simplified Dark Matter (MSDM) framework to quantitatively characterise dark matter (DM) searches at the LHC. We study two MSDM models where the DM is a Dirac fermion which interacts with a vector and axial-vector mediator. The models are characterised by four parameters: mDM, Mmed , gDM and gq, the DM and mediator masses, and the mediator couplings to DM and quarks respectively. The MSDM models accurately capture the full event kinematics, and the dependence on all masses and couplings can be systematically studied. The interpretation of mono-jet searches in this framework can be used to establish an equal-footing comparison with direct detection experiments. For theories with a vector mediator, LHC mono-jet searches possess better sensitivity than direct detection searches for light DM masses (?5 GeV). For axial-vector mediators, LHC and direct detection searches generally probe orthogonal directions in the parameter space. We explore the projected limits of these searches from the ultimate reach of the LHC and multi-ton xenon direct detection experiments, and find that the complementarity of the searches remains. In conclusion, we provide a comparison of limits in the MSDM and effective field theory (EFT) frameworks to highlight the deficiencies of the EFT framework, particularly when exploring the complementarity of mono-jet and direct detection searches.

  1. Characterising dark matter searches at colliders and direct detection experiments: Vector mediators

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Buchmueller, Oliver; Dolan, Matthew J.; Malik, Sarah A.; McCabe, Christopher

    2015-01-09

    We introduce a Minimal Simplified Dark Matter (MSDM) framework to quantitatively characterise dark matter (DM) searches at the LHC. We study two MSDM models where the DM is a Dirac fermion which interacts with a vector and axial-vector mediator. The models are characterised by four parameters: mDM, Mmed , gDM and gq, the DM and mediator masses, and the mediator couplings to DM and quarks respectively. The MSDM models accurately capture the full event kinematics, and the dependence on all masses and couplings can be systematically studied. The interpretation of mono-jet searches in this framework can be used to establishmore »an equal-footing comparison with direct detection experiments. For theories with a vector mediator, LHC mono-jet searches possess better sensitivity than direct detection searches for light DM masses (?5 GeV). For axial-vector mediators, LHC and direct detection searches generally probe orthogonal directions in the parameter space. We explore the projected limits of these searches from the ultimate reach of the LHC and multi-ton xenon direct detection experiments, and find that the complementarity of the searches remains. In conclusion, we provide a comparison of limits in the MSDM and effective field theory (EFT) frameworks to highlight the deficiencies of the EFT framework, particularly when exploring the complementarity of mono-jet and direct detection searches.« less

  2. Characterising Dark Matter Searches at Collider and Direct Detection Experiments: Vector Mediators

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Buchmueller, Oliver; Dolan, Matthew J.; Malik, Sarah A.; McCabe, Christopher

    2015-01-09

    We introduce a Minimal Simplified Dark Matter (MSDM) framework to quantitatively characterise dark matter (DM) searches at the LHC. We study two MSDM models where the DM is a Dirac fermion which interacts with a vector and axial-vector mediator. The models are characterised by four parameters: m DM , M med , g DM and g q, the DM and mediator masses, and the mediator couplings to DM and quarks respectively. The MSDM models accurately capture the full event kinematics, and the dependence on all masses and couplings can be systematically studied. The interpretation of mono-jet searches in this frameworkmore »can be used to establish an equal-footing comparison with direct detection experiments. For theories with a vector mediator, LHC mono-jet searches possess better sensitivity than direct detection searches for light DM masses (?5 GeV). For axial-vector mediators, LHC and direct detection searches generally probe orthogonal directions in the parameter space. We explore the projected limits of these searches from the ultimate reach of the LHC and multi-ton xenon direct detection experiments, and find that the complementarity of the searches remains. Finally, we provide a comparison of limits in the MSDM and effective field theory (EFT) frameworks to highlight the deficiencies of the EFT framework, particularly when exploring the complementarity of mono-jet and direct detection searches.« less

  3. Big Questions: Dark Matter

    SciTech Connect (OSTI)

    Lincoln, Don

    2013-12-05

    Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

  4. Big Questions: Dark Matter

    ScienceCinema (OSTI)

    Lincoln, Don

    2014-08-07

    Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

  5. A Search for Dark Matter with the ZEPLIN II Detector 

    E-Print Network [OSTI]

    Gao, Jianting

    2010-01-14

    WIMP search experiment that attempts to directly detect WIMP interactions using the two-phase xenon approach. The detector measures both scintillation and ionization generated by interactions in a 31 kg liquid xenon target. This approach provides a...

  6. Matter Field, Dark Matter and Dark Energy

    E-Print Network [OSTI]

    Masayasu Tsuge

    2009-03-24

    A model concerning particle theory and cosmology is proposed. Matter field, dark matter and dark energy are created by an energy flow from space to primordial matter fields at the phase transition in the early universe.

  7. The Cryogenic Dark Matter Search and Background Rejection with Event Position Information

    SciTech Connect (OSTI)

    Wang, Gen-sheng

    2005-01-01

    Evidence from observational cosmology and astrophysics indicates that about one third of the universe is matter, but that the known baryonic matter only contributes to the universe at 4%. A large fraction of the universe is cold and non-baryonic matter, which has important role in the universe structure formation and its evolution. The leading candidate for the non-baryonic dark matter is Weakly Interacting Massive Particles (WIMPs), which naturally occurs in the supersymmetry theory in particle physics. The Cryogenic Dark Matter Search (CDMS) experiment is searching for evidence of a WIMP interaction off an atomic nucleus in crystals of Ge and Si by measuring simultaneously the phonon energy and ionization energy of the interaction in the CDMS detectors. The WIMP interaction energy is from a few keV to tens of keV with a rate less than 0.1 events/kg/day. To reach the goal of WIMP detection, the CDMS experiment has been conducted in the Soudan mine with an active muon veto and multistage passive background shields. The CDMS detectors have a low energy threshold and background rejection capabilities based on ionization yield. However, betas from contamination and other radioactive sources produce surface interactions, which have low ionization yield, comparable to that of bulk nuclear interactions. The low-ionization surface electron recoils must be removed in the WIMP search data analysis. An emphasis of this thesis is on developing the method of the surface-interaction rejection using location information of the interactions, phonon energy distributions and phonon timing parameters. The result of the CDMS Soudan run118 92.3 live day WIMP search data analysis is presented, and represents the most sensitive search yet performed.

  8. Optimized dark matter searches in deep observations of Segue 1 with MAGIC

    SciTech Connect (OSTI)

    Aleksi?, J.; Blanch, O.; Ansoldi, S.; Antonelli, L.A.; Bonnoli, G.; Antoranz, P.; Babic, A.; Bangale, P.; De Almeida, U. Barres; Bock, R.K.; Borracci, F.; Barrio, J.A.; Bonnefoy, S.; González, J. Becerra; Berger, K.; Bednarek, W.; Bernardini, E.; Biland, A.; Bretz, T.; Carmona, E. E-mail: jrico@ifae; and others

    2014-02-01

    We present the results of stereoscopic observations of the satellite galaxy Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours of good-quality data, this is the deepest observational campaign on any dwarf galaxy performed so far in the very high energy range of the electromagnetic spectrum. We search this large data sample for signals of dark matter particles in the mass range between 100 GeV and 20 TeV. For this we use the full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral features, like those expected from dark matter annihilation or decay. In particular, we focus our search on gamma-rays produced from different final state Standard Model particles, annihilation with internal bremsstrahlung, monochromatic lines and box-shaped signals. Our results represent the most stringent constraints to the annihilation cross-section or decay lifetime obtained from observations of satellite galaxies, for masses above few hundred GeV. In particular, our strongest limit (95% confidence level) corresponds to a ? 500 GeV dark matter particle annihilating into ?{sup +}?{sup ?}, and is of order (?{sub ann}v) ?  1.2 × 10{sup ?24} cm{sup 3} s{sup ?1} — a factor ? 40 above the (?{sub ann}v) ?  thermal value.

  9. dark matter dark energy inflation

    E-Print Network [OSTI]

    Hu, Wayne

    theory dark matter dark energy inflation The National Science Foundation The Kavli Foundation NSF Site Review November 28-29, 2005 #12;dark matter dark energy inflation NSF Site Visit ­ November 28 - 29, 2005The National Science Foundation The Kavli Foundation The Theoretical Web UHE cosmic rays B

  10. Casting Light on Dark Matter

    E-Print Network [OSTI]

    John Ellis

    2011-06-15

    The prospects for detecting a candidate supersymmetric dark matter particle at the LHC are reviewed, and compared with the prospects for direct and indirect searches for astrophysical dark matter. The discussion is based on a frequentist analysis of the preferred regions of the Minimal supersymmetric extension of the Standard Model with universal soft supersymmetry breaking (the CMSSM). LHC searches may have good chances to observe supersymmetry in the near future - and so may direct searches for astrophysical dark matter particles, whereas indirect searches may require greater sensitivity, at least within the CMSSM.

  11. Search for Weakly Interacting Massive Particles with the First Five-Tower Data from the Cryogenic Dark Matter Search at the Soudan Underground Laboratory

    E-Print Network [OSTI]

    McCarthy, Kevin Ahmad

    We report results from the Cryogenic Dark Matter Search at the Soudan Underground Laboratory (CDMS II) featuring the full complement of 30 detectors. A blind analysis of data taken between October 2006 and July 2007 sets ...

  12. CAST solar axion search with 3^He buffer gas: Closing the hot dark matter gap

    E-Print Network [OSTI]

    M. Arik; S. Aune; K. Barth; A. Belov; S. Borghi; H. Brauninger; G. Cantatore; J. M. Carmona; S. A. Cetin; J. I. Collar; E. Da Riva; T. Dafni; M. Davenport; C. Eleftheriadis; N. Elias; G. Fanourakis; E. Ferrer-Ribas; P. Friedrich; J. Galan; J. A. Garcia; A. Gardikiotis; J. G. Garza; E. N. Gazis; T. Geralis; E. Georgiopoulou; I. Giomataris; S. Gninenko; H. Gomez; M. Gomez Marzoa; E. Gruber; T. Guthorl; R. Hartmann; S. Hauf; F. Haug; M. D. Hasinoff; D. H. H. Hoffmann; F. J. Iguaz; I. G. Irastorza; J. Jacoby; K. Jakovcic; M. Karuza; K. Konigsmann; R. Kotthaus; M. Krcmar; M. Kuster; B. Lakic; P. M. Lang; J. M. Laurent; A. Liolios; A. Ljubicic; V. Lozza; G. Luzon; S. Neff; T. Niinikoski; A. Nordt; T. Papaevangelou; M. J. Pivovaroff; G. Raffelt; H. Riege; A. Rodriguez; M. Rosu; J. Ruz; I. Savvidis; I. Shilon; P. S. Silva; S. K. Solanki; L. Stewart; A. Tomas; M. Tsagri; K. van Bibber; T. Vafeiadis; J. Villar; J. K. Vogel; S. C. Yildiz; K. Zioutas

    2014-09-15

    The CERN Axion Solar Telescope (CAST) has finished its search for solar axions with 3^He buffer gas, covering the search range 0.64 eV < m_a <1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 3.3 x 10^{-10} GeV^{-1} at 95% CL, with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of g_a, for example by the currently discussed next generation helioscope IAXO.

  13. First Results from the Cryogenic Dark Matter Search Experiment at the Deep Site

    SciTech Connect (OSTI)

    Mandic, Vuk

    2004-06-01

    The Cryogenic Dark Matter Search (CDMS) experiment is designed to search for dark matter in the form of the Weakly Interacting Massive Particles (WIMPs). For this purpose, CDMS uses detectors based on crystals of Ge and Si, operated at the temperature of 20 mK, and providing a two-fold signature of an interaction: the ionization and the athermal phonon signals. The two signals, along with the passive and active shielding of the experimental setup, and with the underground experimental sites, allow very effective suppression and rejection of different types of backgrounds. This dissertation presents the commissioning and the results of the first WIMP-search run performed by the CDMS collaboration at the deep underground site at the Soudan mine in Minnesota. We develop different methods of suppressing the dominant background due to the electron-recoil events taking place at the detector surface and we apply these algorithms to the data set. These results place the world's most sensitive limits on the WIMP-nucleon spin-independent elastic-scattering cross-section. Finally, they examine the compatibility of the supersymmetric WIMP-models with the direct-detection experiments (such as CDMS) and discuss the implications of the new CDMS result on these models.

  14. PICASSO, COUPP and PICO - Search for dark matter with bubble chambers

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Amole, C.; Ardid, M.; Asner, D. M.; Baxter, D.; Behnke, E.; Bhattacharjee, P.; Borsodi, H.; Bou-Cabo, M.; Brice, S. J.; Broemmelsiek, D.; et al

    2015-05-29

    The PICASSO and COUPP collaborations use superheated liquid detectors to search for cold dark matter through the direct detection of weakly interacting massive particles (WIMPs). These experiments, located in the underground laboratory of SNOLAB, Canada, detect phase transitions triggered by nuclear recoils in the keV range induced by interactions with WIMPs. We present details of the construction and operation of these detectors as well as the results, obtained by several years of observations. We also introduce PICO, a joint effort of the two collaborations to build a second generation ton-scale bubble chamber with 250 liters of active liquid.

  15. Ultra-Low-Energy Germanium Detector for Neutrino-Nucleus Coherent Scattering and Dark Matter Searches

    E-Print Network [OSTI]

    Henry T. Wong

    2008-03-01

    The status and plans of a research program on the development of ultra-low-energy germanium detectors with sub-keV sensitivities are reported. We survey the scientific goals which include the observation of neutrino-nucleus coherent scattering, the studies of neutrino magnetic moments, as well as the searches of WIMP dark matter. In particular, a threshold of 100-200 eV and a sub-keV background comparable to underground experiments were achieved with prototype detectors. New limits were set for WIMPs with mass between 3-6 GeV. The prospects of the realization of full-scale experiments are discussed.

  16. Asymptotically Safe Dark Matter

    E-Print Network [OSTI]

    Francesco Sannino; Ian M. Shoemaker

    2015-08-05

    We introduce a new paradigm for dark matter (DM) interactions in which the interaction strength is asymptotically safe. In models of this type, the coupling strength is small at low energies but increases at higher energies, and asymptotically approaches a finite constant value. The resulting phenomenology of this "asymptotically safe DM" is quite distinct. One interesting effect of this is to partially offset the low-energy constraints from direct detection experiments without affecting thermal freeze-out processes which occur at higher energies. High-energy collider and indirect annihilation searches are the primary ways to constrain or discover asymptotically safe dark matter.

  17. Safe Dark Matter

    E-Print Network [OSTI]

    Francesco Sannino; Ian M. Shoemaker

    2015-07-29

    We introduce a new paradigm for dark matter (DM) interactions in which the interaction strength is asymptotically safe. In models of this type, the coupling strength is small at low energies but increases at higher energies, and asymptotically approaches a finite constant value. The resulting phenomenology of this "safe DM" is quite distinct. One interesting effect of this is to partially offset the low-energy constraints from direct detection experiments without affecting thermal freeze-out processes which occur at higher energies. High-energy collider and indirect annihilation searches are the primary ways to constrain or discover safe dark matter.

  18. Positronium Portal into Hidden Sector: A new Experiment to Search for Mirror Dark Matter

    E-Print Network [OSTI]

    Paolo Crivelli; Alexander Belov; Ulisse Gendotti; Sergei Gninenko; Andre Rubbia

    2010-07-19

    The understanding of the origin of dark matter has great importance for cosmology and particle physics. Several interesting extensions of the standard model dealing with solution of this problem motivate the concept of hidden sectors consisting of SU(3)xSU(2)_LxU(1)_Y singlet fields. Among these models, the mirror matter model is certainly one of the most interesting. The model explains the origin of parity violation in weak interactions, it could also explain the baryon asymmetry of the Universe and provide a natural ground for the explanation of dark matter. The mirror matter could have a portal to our world through photon-mirror photon mixing (epsilon). This mixing would lead to orthopositronium (o-Ps) to mirror orthopositronium oscillations, the experimental signature of which is the apparently invisible decay of o-Ps. In this paper, we describe an experiment to search for the decay o-Ps -> invisible in vacuum by using a pulsed slow positron beam and a massive 4pi BGO crystal calorimeter. The developed high efficiency positron tagging system, the low calorimeter energy threshold and high hermiticity allow the expected sensitivity in mixing strength to be epsilon about 10^-9, which is more than one order of magnitude below the current Big Bang Nucleosynthesis limit and in a region of parameter space of great theoretical and phenomenological interest. The vacuum experiment with such sensitivity is particularly timely in light of the recent DAMA/LIBRA observations of the annual modulation signal consistent with a mirror type dark matter interpretation.

  19. Intrinsic neutron background of nuclear emulsions for directional Dark Matter searches

    E-Print Network [OSTI]

    Aleksandrov, A; Buonaura, A; Consiglio, L; D'Ambrosio, N; De Lellis, G; Di Crescenzo, A; Di Marco, N; Di Vacri, M L; Furuya, S; Galati, G; Gentile, V; Katsuragawa, T; Laubenstein, M; Lauria, A; Loverre, P F; Machii, S; Monacelli, P; Montesi, M C; Naka, T; Pupilli, F; Rosa, G; Sato, O; Tioukov, V; Umemoto, A; Yoshimoto, M

    2015-01-01

    Recent developments of the nuclear emulsion technology led to the production of films with nanometric silver halide grains suitable to track low energy nuclear recoils with submicrometric length. This improvement opens the way to a directional Dark Matter detection, thus providing an innovative and complementary approach to the on-going WIMP searches. An important background source for these searches is represented by neutron-induced nuclear recoils that can mimic the WIMP signal. In this paper we provide an estimation of the contribution to this background from the intrinsic radioactive contamination of nuclear emulsions. We also report the induced background as a function of the read-out threshold, by using a GEANT4 simulation of the nuclear emulsion, showing that it amounts to about 0.02 neutrons per year per kilogram, fully compatible with the design of a 10 kg$\\times$year exposure.

  20. Low-mass dark matter search results from full exposure of PandaX-I experiment

    E-Print Network [OSTI]

    Xiao, Xiang; Tan, Andy; Chen, Yunhua; Cui, Xiangyi; Fang, Deqing; Fu, Changbo; Giboni, Karl L; Gong, Haowei; Guo, Guodong; He, Ming; Ji, Xiangdong; Ju, Yonglin; Lei, Siao; Li, Shaoli; Lin, Qing; Liu, Huaxuan; Liu, Jianglai; Liu, Xiang; Lorenzon, Wolfgang; Ma, Yugang; Mao, Yajun; Ni, Kaixuan; Pushkin, Kirill; Ren, Xiangxiang; Schubnell, Michael; Shen, Manbing; Shi, Yuji; Stephenson, Scott; Wang, Hongwei; Wang, Jiming; Wang, Meng; Wang, Siguang; Wang, Xuming; Wang, Zhou; Wu, Shiyong; Xiao, Mengjiao; Xie, Pengwei; Yan, Binbin; You, Yinghui; Zeng, Xionghui; Zhang, Tao; Zhao, Li; Zhou, Xiaopeng; Zhu, Zhonghua

    2015-01-01

    We report the results of a weakly-interacting massive particle (WIMP) dark matter search using the full 80.1\\;live-day exposure of the first stage of the PandaX experiment (PandaX-I) located in the China Jin-Ping Underground Laboratory. The PandaX-I detector has been optimized for detecting low-mass WIMPs, achieving a photon detection efficiency of 9.6\\%. With a fiducial liquid xenon target mass of 54.0\\,kg, no significant excess event were found above the expected background. A profile likelihood analysis confirms our earlier finding that the PandaX-I data disfavor all positive low-mass WIMP signals reported in the literature under standard assumptions. A stringent bound on the low mass WIMP is set at WIMP mass below 10\\,GeV/c$^2$, demonstrating that liquid xenon detectors can be competitive for low-mass WIMP searches.

  1. Low-mass dark matter search results from full exposure of PandaX-I experiment

    E-Print Network [OSTI]

    PandaX Collaboration; Xiang Xiao; Xun Chen; Andi Tan; Yunhua Chen; Xiangyi Cui; Deqing Fang; Changbo Fu; Karl L. Giboni; Haowei Gong; Guodong Guo; Ming He; Xiangdong Ji; Yonglin Ju; Siao Lei; Shaoli Li; Qing Lin; Huaxuan Liu; Jianglai Liu; Xiang Liu; Wolfgang Lorenzon; Yugang Ma; Yajun Mao; Kaixuan Ni; Kirill Pushkin; Xiangxiang Ren; Michael Schubnell; Manbin Shen; Yuji Shi; Scott Stephenson; Hongwei Wang; Jiming Wang; Meng Wang; Siguang Wang; Xuming Wang; Zhou Wang; Shiyong Wu; Mengjiao Xiao; Pengwei Xie; Binbin Yan; Yinghui You; Xionghui Zeng; Tao Zhang; Li Zhao; Xiaopeng Zhou; Zhonghua Zhu

    2015-08-20

    We report the results of a weakly-interacting massive particle (WIMP) dark matter search using the full 80.1\\;live-day exposure of the first stage of the PandaX experiment (PandaX-I) located in the China Jin-Ping Underground Laboratory. The PandaX-I detector has been optimized for detecting low-mass WIMPs, achieving a photon detection efficiency of 9.6\\%. With a fiducial liquid xenon target mass of 54.0\\,kg, no significant excess event were found above the expected background. A profile likelihood analysis confirms our earlier finding that the PandaX-I data disfavor all positive low-mass WIMP signals reported in the literature under standard assumptions. A stringent bound on the low mass WIMP is set at WIMP mass below 10\\,GeV/c$^2$, demonstrating that liquid xenon detectors can be competitive for low-mass WIMP searches.

  2. Particle identification with the AMS-02 RICH detector: search for dark matter with antideuterons

    E-Print Network [OSTI]

    Luísa Arruda; Fernando Barão; Rui Pereira

    2007-10-04

    The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be installed on the International Space Station (ISS) for at least 3 years, is a detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to a few hundred GeV, using state-of-the art particle identification techniques. It is equipped with several subsystems, one of which is a proximity focusing Ring Imaging Cherenkov (RICH) detector equipped with a dual radiator (aerogel+NaF), a lateral conical mirror and a detection plane made of 680 photomultipliers and light guides, enabling precise measurements of particle electric charge and velocity (Delta beta / beta ~ 10^-3 and 10^-4 for Z=1 and Z=10-20, respectively) at kinetic energies of a few GeV/nucleon. Combining velocity measurements with data on particle rigidity from the AMS-02 Tracker (Delta R / R ~ 2% for R=1-10 GV) it is possible to obtain a reliable measurement for particle mass. One of the main topics of the AMS-02 physics program is the search for indirect signatures of dark matter. Experimental data indicate that dark, non-baryonic matter of unknown composition is much more abundant than baryonic matter, accounting for a large fraction of the energy content of the Universe. Apart from antideuterons produced in cosmic-ray propagation, the annihilation of dark matter will produce additional antideuteron fluxes. Detailed Monte Carlo simulations of AMS-02 have been used to evaluate the detector's performance for mass separation, a key issue for anti-D/anti-p separation. Results of these studies are presented.

  3. Simplified Models for Dark Matter and Missing Energy Searches at the LHC

    E-Print Network [OSTI]

    Jalal Abdallah; Adi Ashkenazi; Antonio Boveia; Giorgio Busoni; Andrea De Simone; Caterina Doglioni; Aielet Efrati; Erez Etzion; Johanna Gramling; Thomas Jacques; Tongyan Lin; Enrico Morgante; Michele Papucci; Bjoern Penning; Antonio Walter Riotto; Thomas Rizzo; David Salek; Steven Schramm; Oren Slone; Yotam Soreq; Alessandro Vichi; Tomer Volansky; Itay Yavin; Ning Zhou; Kathryn Zurek

    2014-10-01

    The study of collision events with missing energy as searches for the dark matter (DM) component of the Universe are an essential part of the extensive program looking for new physics at the LHC. Given the unknown nature of DM, the interpretation of such searches should be made broad and inclusive. This report reviews the usage of simplified models in the interpretation of missing energy searches. We begin with a brief discussion of the utility and limitation of the effective field theory approach to this problem. The bulk of the report is then devoted to several different simplified models and their signatures, including s-channel and t-channel processes. A common feature of simplified models for DM is the presence of additional particles that mediate the interactions between the Standard Model and the particle that makes up DM. We consider these in detail and emphasize the importance of their inclusion as final states in any coherent interpretation. We also review some of the experimental progress in the field, new signatures, and other aspects of the searches themselves. We conclude with comments and recommendations regarding the use of simplified models in Run-II of the LHC.

  4. Indirect search for dark matter with AMS in positrons, gamma and antiprotons channels

    E-Print Network [OSTI]

    Diego Casadei

    2006-09-04

    The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station, will provide data on cosmic radiations in a large energy range. The main physics goals in the astroparticle domain are the antimatter and the dark matter searches. Dark matter should be composed of non baryonic weakly interacting massive particles, a good candidate being the lightest SUSY particle in R-parity conserving models. As a prototype for the AMS-02 experiment, the AMS-01 particle spectrometer was flown on the Space Shuttle Discovery in near earth orbit for a ten day mission in June 1998. The direct identification of positrons in AMS-01 was limited to energies below 3 GeV due to the vast proton background and the characteristics of the subdetectors, but the sensitivity towards higher energies (up to 40 GeV) was extended by identifying positrons through the conversion of bremsstrahlung photons. AMS-02 will greatly improve the accuracy on the positron spectrum, which will be measured up to 300 GeV, together with the antiproton and $\\gamma$-ray flux, thus providing a unique chance to measure all relevant neutralino decay channels with the same experiment.

  5. Indirect search for dark matter with AMS in positrons, gamma and antiprotons channels

    E-Print Network [OSTI]

    Casadei, D

    2007-01-01

    The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station, will provide data on cosmic radiations in a large energy range. The main physics goals in the astroparticle domain are the antimatter and the dark matter searches. Dark matter should be composed of non baryonic weakly interacting massive particles, a good candidate being the lightest SUSY particle in R-parity conserving models. As a prototype for the AMS-02 experiment, the AMS-01 particle spectrometer was flown on the Space Shuttle Discovery in near earth orbit for a ten day mission in June 1998. The direct identification of positrons in AMS-01 was limited to energies below 3 GeV due to the vast proton background and the characteristics of the subdetectors, but the sensitivity towards higher energies (up to 40 GeV) was extended by identifying positrons through the conversion of bremsstrahlung photons. AMS-02 will greatly improve the accuracy on the positron spectrum, which will be measured up to 300 GeV, together with t...

  6. Results From The Two-tower Run Of The Cryogenic Dark Matter Search

    E-Print Network [OSTI]

    Reisetter, A J

    2005-01-01

    The Cryogenic Dark Matter Search has completed two runs at the Soudan Underground Laboratory In the second, two towers of detectors were operated from March to August 2004. CDMS used Ge and Si ZIP (Z-sensitive, Ionization, and Phonon) detectors, operated at 50mK, to look for Weakly Interacting Massive Particles (WIMPS) which may make up most of the dark matter in our universe. These detectors are surrounded by lead and polyethylene shielding as well as an active muon veto. These shields, as well as the overburden of Soudan rock, provide a low background environment for the detectors. The ZIP detectors record the ratio of ionization signal to phonon signal to discriminate between nuclear recoils, characteristic of WIMPS and neutrons, and electron recoils, characteristic of gamma and beta backgrounds. They also provide timing information from the four phonon channels that is used to reject surface events, for which ionization collection is poor. A blind analysis, defined using calibration data taken in situ thr...

  7. Search for dark matter in events with heavy quarks and missing transverse momentum in pp collisions with the ATLAS detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.

    2015-02-24

    This article reports on a search for dark matter pair production in association with bottom or top quarks in 20.3 fb–1 of pp collisions collected at ?s=8 TeV by the ATLAS detector at the LHC. Events with large missing transverse momentum are selected when produced in association with high-momentum jets of which one or more are identified as jets containing b-quarks. Final states with top quarks are selected by requiring a high jet multiplicity and in some cases a single lepton. The data are found to be consistent with the Standard Model expectations and limits are set on the massmore »scale of effective field theories that describe scalar and tensor interactions between dark matter and Standard Model particles. Limits on the dark-matter–nucleon cross-section for spin-independent and spin-dependent interactions are also provided. These limits are particularly strong for low-mass dark matter. Using a simplified model, constraints are set on the mass of dark matter and of a colored mediator suitable to explain a possible signal of annihilating dark matter.« less

  8. Preliminary Limits on the WIMP-Nucleon Cross Section from the Cryogenic Dark Matter Search (CDMS)

    E-Print Network [OSTI]

    DS Akerib; PD Barnes Jr; DA Bauer; PL Brink; B Cabrera; DO Caldwell; RM Clarke; A Da Silva; AK Davies; BL Dougherty; KD Irwin; RJ Gaitskell; SR Golwala; EE Haller; J Jochum; WB Knowlton; V Kuzminov; SW Nam; V Novikov; MJ Penn; TA Perera; RR Ross; B Sadoulet; RW Schnee; T Shutt; A Smith; AH Sonnenschein; AL Spadafora; WK Stockwell; S Yellin; BA Young

    1997-12-30

    We are conducting an experiment to search for WIMPs, or weakly-interacting massive particles, in the galactic halo using terrestrial detectors. This generic class of hypothetical particles, whose properties are similar to those predicted by extensions of the standard model of particle physics, could comprise the cold component of non-baryonic dark matter. We describe our experiment, which is based on cooled germanium and silicon detectors in a shielded low-background cryostat. The detectors achieve a high degree of background rejection through the simultaneous measurement of the energy in phonons and ionization. Using exposures on the order of one kilogram-day from initial runs of our experiment, we have achieved (preliminary) upper limits on the WIMP-nucleon cross section that are comparable to much longer runs of other experiments.

  9. Searches for dark matter signals in simplified models at future hadron colliders

    E-Print Network [OSTI]

    Qian-Fei Xiang; Xiao-Jun Bi; Peng-Fei Yin; Zhao-Huan Yu

    2015-03-10

    We study the prospect of dark matter (DM) searches in the monojet channel at future $pp$ colliders with center-of-mass energies of 33, 50, and 100~TeV. We consider a class of simplified models in which a vector boson connecting DM particles to quarks is introduced. Comparing with studies in the effective field theory, the present framework gives more reasonable production rates and kinematics of the DM signatures. We estimate the sensitivities of future colliders with an integrated luminosity of 3 $ab^{-1}$ to the DM-induced monojet signature and show the parameter space that can be explored. The constraints from direct and indirect DM detection experiments are compared with the future collider sensitivities. We find that the future collider detection will be much more sensitive than the indirect detection for the vector interaction, and have better sensitivities than those of the direct detection by several orders of magnitude for the axial vector interaction.

  10. Prospects of cold dark matter searches with an ultra-low-energy germanium detector

    E-Print Network [OSTI]

    H. T. Wong

    2007-11-08

    The report describes the research program on the development of ultra-low-energy germanium detectors, with emphasis on WIMP dark matter searches. A threshold of 100 eV is achieved with a 20 g detector array, providing a unique probe to the low-mas WIMP. Present data at a surface laboratory is expected to give rise to comparable sensitivities with the existing limits at the $\\rm{5 - 10 GeV}$ WIMP-mass range. The projected parameter space to be probed with a full-scale, kilogram mass-range experiment is presented. Such a detector would also allow the studies of neutrino-nucleus coherent scattering and neutrino magnetic moments.

  11. First dark matter search results from the PandaX-I experiment

    E-Print Network [OSTI]

    Xiao, Mengjiao; Zhao, Li; Cao, Xiguang; Chen, Xun; Chen, Yunhua; Cui, Xiangyi; Fang, Deqing; Fu, Changbo; Giboni, Karl L; Gong, Haowei; Guo, Guodong; Hu, Jie; Huang, Xingtao; Ji, Xiangdong; Ju, Yonglin; Lei, Siao; Li, Shaoli; Lin, Qing; Liu, Huaxuan; Liu, Jianglai; Liu, Xiang; Lorenzon, Wolfgang; Ma, Yugang; Mao, Yajun; Ni, Kaixuan; Pushkin, Kirill; Ren, Xiangxiang; Schubnell, Michael; Shen, Manbing; Stephenson, Scott; Tan, Andi; Tarle, Greg; Wang, Hongwei; Wang, Jimin; Wang, Meng; Wang, Xuming; Wang, Zhou; Wei, Yuehuan; Wu, Shiyong; Xie, Pengwei; You, Yinghui; Zeng, Xionghui; Zhang, Hua; Zhang, Tao; Zhu, Zhonghua

    2014-01-01

    We report on the first dark-matter (DM) search results from PandaX-I, a low threshold dual-phase xenon experiment operating at the China Jinping Underground Laboratory. In the 37-kg liquid xenon target with 17.4 live-days of exposure, no DM particle candidate event was found. This result sets a stringent limit for low-mass DM particles and disfavors the interpretation of previously-reported positive experimental results. The minimum upper limit, $3.7\\times10^{-44}$\\,cm$^2$, for the spin-independent isoscalar DM-particle-nucleon scattering cross section is obtained at a DM-particle mass of 49\\,GeV/c$^2$ at 90\\% confidence level.

  12. First dark matter search results from the PandaX-I experiment

    E-Print Network [OSTI]

    PandaX Collaboration; Mengjiao Xiao; Xiang Xiao; Li Zhao; Xiguang Cao; Xun Chen; Yunhua Chen; Xiangyi Cui; Deqing Fang; Changbo Fu; Karl L. Giboni; Haowei Gong; Guodong Guo; Jie Hu; Xingtao Huang; Xiangdong Ji; Yonglin Ju; Siao Lei; Shaoli Li; Qing Lin; Huaxuan Liu; Jianglai Liu; Xiang Liu; Wolfgang Lorenzon; Yugang Ma; Yajun Mao; Kaixuan Ni; Kirill Pushkin; Xiangxiang Ren; Michael Schubnell; Manbing Shen; Scott Stephenson; Andi Tan; Greg Tarle; Hongwei Wang; Jimin Wang; Meng Wang; Xuming Wang; Zhou Wang; Yuehuan Wei; Shiyong Wu; Pengwei Xie; Yinghui You; Xionghui Zeng; Hua Zhang; Tao Zhang; Zhonghua Zhu

    2014-09-04

    We report on the first dark-matter (DM) search results from PandaX-I, a low threshold dual-phase xenon experiment operating at the China Jinping Underground Laboratory. In the 37-kg liquid xenon target with 17.4 live-days of exposure, no DM particle candidate event was found. This result sets a stringent limit for low-mass DM particles and disfavors the interpretation of previously-reported positive experimental results. The minimum upper limit, $3.7\\times10^{-44}$\\,cm$^2$, for the spin-independent isoscalar DM-particle-nucleon scattering cross section is obtained at a DM-particle mass of 49\\,GeV/c$^2$ at 90\\% confidence level.

  13. Implications of Direct Dark Matter Constraints for Minimal Supersymmetric Standard Model Higgs Boson Searches at the Tevatron

    E-Print Network [OSTI]

    Marcela Carena; Dan Hooper; Peter Skands

    2006-08-22

    Searches for the Minimal Supersymmetric Standard Model (MSSM) Higgs bosons are among the most promising channels for exploring new physics at the Tevatron. In particular, interesting regions of large $\\tan \\beta$ and small $m_A$ are probed by searches for heavy neutral Higgs bosons, A and H, when they decay to $\\tau^+ \\tau^-$ and $b\\bar{b}$. At the same time, direct searches for dark matter, such as CDMS, attempt to observe neutralino dark matter particles scattering elastically off nuclei. This can occur through t-channel Higgs exchange, which has a large cross section in the case of large $\\tan \\beta$ and small $m_A$. As a result, there is a natural interplay between the heavy, neutral Higgs searches at the Tevatron and the region of parameter space explored by CDMS. We show that if the lightest neutralino makes up the dark matter of our universe, current limits from CDMS strongly constrain the prospects of heavy, neutral MSSM Higgs discovery at the Tevatron (at 3 sigma with 4 fb^-1 per experiment) unless $|\\mu| \\gsim$ 400 GeV. The limits of CDMS projected for 2007 will increase this constraint to $|\\mu| \\gsim$ 800 GeV. On the other hand, if CDMS does observe neutralino dark matter in the near future, it will make the discovery of heavy, neutral MSSM Higgs bosons far more likely at the Tevatron.

  14. Asymmetric dark matter

    SciTech Connect (OSTI)

    Kumar, Jason

    2014-06-24

    We review the theoretical framework underlying models of asymmetric dark matter, describe astrophysical constraints which arise from observations of neutron stars, and discuss the prospects for detecting asymmetric dark matter.

  15. Search for Low-Mass Dark Matter at BABAR Echenard, Bertrand;...

    Office of Scientific and Technical Information (OSTI)

    Low-Mass Dark Matter at BABAR Echenard, Bertrand; Caltech Experiment-HEP,HEPEX Experiment-HEP,HEPEX Abstract Not Provided http:www-public.slac.stanford.eduSciDoc...

  16. A search for signatures of dark matter in the AMS-01 electron and antiproton spectrum

    E-Print Network [OSTI]

    Carosi, Gianpaolo Patrick

    2006-01-01

    If dark matter consists of Weakly Interacting Massive Particles (WIMPs), such as the supersymmetric neutralino, various theories predict that their annihilation in the galaxy can give rise to anomalous features in the ...

  17. Advancing the search for dark matter : from CDMS II to SuperCDMS

    E-Print Network [OSTI]

    Hertel, Scott A. (Scott Alexander)

    2012-01-01

    An overwhelming proportion of the universe (83% by mass) is composed of particles we know next to nothing about. Detecting these dark matter particles directly, through hypothesized weak-force-mediated recoils with nuclear ...

  18. Dark Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB Packet HanfordDOEDaniel Shechtman andDark Fiber Testbed Network

  19. WIMP Dark Matter Limit-Direct Detection Data and Sensitivity Plots from the Cryogenic Dark Matter Search II and the University of California at Santa Barbara

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Expectations for non-baryonic dark matter are founded principally in Big Bang nucleosynthesis calculations, which indicate that the missing mass of the universe is not likely to be baryonic. The supersymmetric standard model (SUSY) offers a promising framework for expectations of particle species which could satisfy the observed properties of dark matter. WIMPs are the most likely SUSY candidate for a dark matter particle. The High Energy Physics Group at University of California, Santa Barbara, is part of the CDMSII Collaboration and have provided the Interactive Plotter for WIMP Dark Matter Limit-Direct Detection Data on their website. They invite other collaborations working on dark matter research to submit datasets and, as a result, have more than 150 data sets now available for use with the plotting tool. The published source of the data is provided with each data set.

  20. Aldo Morselli, INFN & Universit di Roma Tor Vergata, aldo.morselli@roma2.infn.it 1 Dark Matter Indirect Search

    E-Print Network [OSTI]

    Morselli, Aldo

    Aldo Morselli, INFN & Università di Roma Tor Vergata, aldo.morselli@roma2.infn.it 1 Dark Matter Indirect Search : News from the sky Prospects for the detection of Dark Matter CIECEM Matalacañs, Spain & Moskalenko, available on the Web) semi-analitical solution: Maurin et al, astro-ph/0101231 #12;Aldo Morselli

  1. Hot-dark matter, cold dark matter and accelerating universe

    E-Print Network [OSTI]

    Abbas Farmany; Amin Farmany; Mohammad Mahmoodi

    2006-07-07

    The Friedman equation is solved for a universe contains hotdark matter and cold dark matter. In this scenario, hot-dark matter drives an accelerating universe no cold dark matter.

  2. Updated Search for Spectral Lines from Galactic Dark Matter Interactions with Pass 8 Data from the Fermi Large Area Telescope

    E-Print Network [OSTI]

    ,

    2015-01-01

    Dark matter in the Milky Way may annihilate directly into gamma rays, producing a monoenergetic spectral line. Therefore, detecting such a signature would be strong evidence for dark matter annihilation or decay. We search for spectral lines in the Fermi Large Area Telescope observations of the Milky Way halo in the energy range 200 MeV to 500 GeV using analysis methods from our most recent line searches. The main improvements relative to previous works are our use of 5.8 years of data reprocessed with the Pass 8 event-level analysis and the additional data resulting from the modified observing strategy designed to increase exposure of the Galactic center region. We searched in five sky regions selected to optimize sensitivity to different theoretically-motivated dark matter scenarios and find no significant detections. In addition to presenting the results from our search for lines, we also investigate the previously reported tentative detection of a line at 133 GeV using the new Pass 8 data.

  3. Searching for Vector Dark Matter by Higgs Portal at the LHC

    E-Print Network [OSTI]

    Chuan-Hung Chen; Takaaki Nomura

    2015-07-10

    A Higgs portal dark matter model for explaining the gamma-ray excess from Galactic center could be realized in the extension of local $SU(2)_X$ gauge symmetry with one quadruplet. Due to the residual $Z_3$ discrete symmetry of $SU(2)_X$, the new gauge bosons are the stable dark matter candidates. Due to the mixture of standard model Higgs doublet and introduced quadruplet, dark matter could annihilate into the standard model particles through Higgs and new scalar portals. We study the discovery significance of the vector dark matter at the LHC, where the involving parameters are consistent with the constraints from relic density and direct detection and with the data of Galactic center gamma-ray. With $\\sqrt{s}=14$ TeV and luminosities of $100$ and $300$ fb$^{-1}$, we find that the discovery significance of $S/\\sqrt{B}=5$ could be easily reached if the production of dark matter is through the invisible decays of Higgs and new scalar boson.

  4. Discrete dark matter

    SciTech Connect (OSTI)

    Hirsch, M.; Morisi, S.; Peinado, E.; Valle, J. W. F. [AHEP Group, Institut de Fisica Corpuscular--C.S.I.C./Universitat de Valencia, Edificio Institutos de Paterna, Apartado 22085, E-46071 Valencia (Spain)

    2010-12-01

    We propose a new motivation for the stability of dark matter (DM). We suggest that the same non-Abelian discrete flavor symmetry which accounts for the observed pattern of neutrino oscillations, spontaneously breaks to a Z{sub 2} subgroup which renders DM stable. The simplest scheme leads to a scalar doublet DM potentially detectable in nuclear recoil experiments, inverse neutrino mass hierarchy, hence a neutrinoless double beta decay rate accessible to upcoming searches, while {theta}{sub 13}=0 gives no CP violation in neutrino oscillations.

  5. Impact of Coherent Neutrino Nucleus Scattering on Direct Dark Matter Searches based on CaWO$_4$ Crystals

    E-Print Network [OSTI]

    A. Gütlein; G. Angloher; A. Bento; C. Bucci; L. Canonica; A. Erb; F. v. Feilitzsch; N. Ferreiro Iachellini; P. Gorla; D. Hauff; J. Jochum; M. Kiefer; H. Kluck; H. Kraus; J. -C. Lanfranchi; J. Loebell; A. Münster; F. Petricca; W. Potzel; F. Pröbst; F. Reindl; S. Roth; K. Rottler; C. Sailer; K. Schäffner; J. Schieck; S. Schönert; W. Seidel; M. v. Sivers; L. Stodolsky; C. Strandhagen; R. Strauss; A. Tanzke; M. Uffinger; A. Ulrich; I. Usherov; S. Wawoczny; M. Willers; M. Wüstrich; A. Zöller

    2015-03-17

    Atmospheric and solar neutrinos scattering coherently off target nuclei will be an important background source for the next generation of direct dark matter searches. In this work we focus on calcium tungstate as target material. For comparison with existing works we calculate the neutrino floor indicating which sensitivities can be reached before the neutrino background appears. In addition, we investigate the sensitivities of future direct dark matter searches using CRESST-II like detectors. Extending previous works we take into account achievable energy resolutions and thresholds as well as beta and gamma backgrounds for this investigation. We show that an exploration of WIMP-nucleon cross sections below the neutrino floor is possible for exposures of $\\gtrsim10$ kg-years or higher. In the third part we show that a first detection of coherent neutrino nucleus scattering of atmospheric and solar neutrinos using the same detectors and the backgrounds is feasible for exposures of $\\gtrsim50$ kg-years.

  6. Dipolar Dark Matter

    E-Print Network [OSTI]

    Luc Blanchet; Lavinia Heisenberg

    2015-05-19

    Massive gravity theories have been developed as viable IR modifications of gravity motivated by dark energy and the problem of the cosmological constant. On the other hand, modified gravity and modified dark matter theories were developed with the aim of solving the problems of standard cold dark matter at galactic scales. Here we propose to adapt the framework of ghost-free massive bigravity theories to reformulate the problem of dark matter at galactic scales. We investigate a promising alternative to dark matter called dipolar dark matter (DDM) in which two different species of dark matter are separately coupled to the two metrics of bigravity and are linked together by an internal vector field. We show that this model successfully reproduces the phenomenology of dark matter at galactic scales (i.e. MOND) as a result of a mechanism of gravitational polarisation. The model is safe in the gravitational sector, but because the two types of dark matter interact through the vector field, a ghostly degree of freedom in the decoupling limit is reintroduced in the dark matter sector. Crucial questions to address in future work is whether the polarisation mechanism can be realized in absence of ghosts, and what are the cosmological implications of the model.

  7. Search for dark matter, extra dimensions, and unparticles in monojet events in proton–proton collisions at ?s = 8 TeV

    E-Print Network [OSTI]

    Apyan, Aram

    Results are presented from a search for particle dark matter (DM), extra dimensions, and unparticles using events containing a jet and an imbalance in transverse momentum. The data were collected by the CMS detector in ...

  8. Exclusion limits on the WIMP-nucleon cross-section from the Cryogenic Dark Matter Search

    E-Print Network [OSTI]

    CDMS Collaboration

    2002-08-16

    The Cryogenic Dark Matter Search (CDMS) employs low-temperature Ge and Si detectors to search for Weakly Interacting Massive Particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. For recoil energies above 10 keV, events due to background photons are rejected with >99.9% efficiency, and surface events are rejected with >95% efficiency. The estimate of the background due to neutrons is based primarily on the observation of multiple-scatter events that should all be neutrons. Data selection is determined primarily by examining calibration data and vetoed events. Resulting efficiencies should be accurate to about 10%. Results of CDMS data from 1998 and 1999 with a relaxed fiducial-volume cut (resulting in 15.8 kg-days exposure on Ge) are consistent with an earlier analysis with a more restrictive fiducial-volume cut. Twenty-three WIMP candidate events are observed, but these events are consistent with a background from neutrons in all ways tested. Resulting limits on the spin-independent WIMP-nucleon elastic-scattering cross-section exclude unexplored parameter space for WIMPs with masses between 10-70 GeV c^{-2}. These limits border, but do not exclude, parameter space allowed by supersymmetry models and accelerator constraints. Results are compatible with some regions reported as allowed at 3-sigma by the annual-modulation measurement of the DAMA collaboration. However, under the assumptions of standard WIMP interactions and a standard halo, the results are incompatible with the DAMA most likely value at >99.9% CL, and are incompatible with the model-independent annual-modulation signal of DAMA at 99.99% CL in the asymptotic limit.

  9. The Cryogenic Dark Matter Search: First 5-Tower Data and Improved Understanding of Ionization Collection

    SciTech Connect (OSTI)

    Bailey, Catherine N.

    2010-01-01

    The Cryogenic Dark Matter Search (CDMS) is searching for Weakly Interacting Massive Particles (WIMPs) with cryogenic particle detectors. These detectors have the ability to discriminate between nuclear recoil candidate and electron recoil background events by collecting both phonon and ionization energy from recoils in the detector crystals. The CDMS-II experiment has completed analysis of the first data runs with 30 semiconductor detectors at the Soudan Underground Laboratory, resulting in a world leading WIMP-nucleon spin-independent cross section limit for WIMP masses above 44 GeV/c{sup 2}. As CDMS aims to achieve greater WIMP sensitivity, it is necessary to increase the detector mass and discrimination between signal and background events. Incomplete ionization collection results in the largest background in the CDMS detectors as this causes electron recoil background interactions to appear as false candidate events. Two primary causes of incomplete ionization collection are surface and bulk trapping. Recent work has been focused on reducing surface trapping through the modification of fabrication methods for future detectors. Analyzing data taken with test devices has shown that hydrogen passivation of the amorphous silicon blocking layer worsens surface trapping. Additional data has shown that the iron-ion implantation used to lower the critical temperature of the tungsten transition-edge sensors causes a degradation of the ionization collection. Using selective implantation on future detectors may improve ionization collection for events near the phonon side detector surface. Bulk trapping is minimized by neutralizing ionized lattice impurities. Detector investigations at testing facilities and in situ at the experimental site have provided methods to optimize the neutralization process and monitor running conditions to maintain full ionization collection. This work details my contribution to the 5-tower data taking, monitoring, and analysis effort as well as the SuperCDMS detector development with the focus on monitoring and improving ionization collection in the detectors.

  10. Tools for model-independent bounds in direct dark matter searches

    SciTech Connect (OSTI)

    Cirelli, Marco

    2013-10-01

    We discuss a framework (based on non-relativistic operators) and a self-contained set of numerical tools to derive the bounds from some current direct detection experiments on virtually any arbitrary model of Dark Matter elastically scattering on nuclei.

  11. Low Energy Nuclear Recoil Response in Xenon Gas for Low Mass Dark Matter WIMP Search 

    E-Print Network [OSTI]

    Sofka, Clement James

    2014-04-16

    these "dark" sources of matter/energy is the single most important concern in the modern quest for understanding Nature. We live in an epoch that is almost certainly characterized by a at, expanding Universe. Coupling this with the wealth of astrophysical...

  12. Non-Abelian dark matter and dark radiation

    E-Print Network [OSTI]

    Manuel A. Buen-Abad; Gustavo Marques-Tavares; Martin Schmaltz

    2015-07-16

    We propose a new class of dark matter models with unusual phenomenology. What is ordinary about our models is that dark matter particles are WIMPs, they are weakly coupled to the Standard Model and have weak scale masses. What is unusual is that they come in multiplets of a new "dark" non-Abelian gauge group with milli-weak coupling. The massless dark gluons of this dark gauge group contribute to the energy density of the universe as a form of weakly self-interacting dark radiation. In this paper we explore the consequences of having i.) dark matter in multiplets ii.) self-interacting dark radiation and iii.) dark matter which is weakly coupled to dark radiation. We find that i.) dark matter cross sections are modified by multiplicity factors which have significant consequences for collider searches and indirect detection, ii.) dark gluons have thermal abundances which affect the CMB as dark radiation. Unlike additional massless neutrino species the dark gluons are interacting and have vanishing viscosity and iii.) the coupling of dark radiation to dark matter represents a new mechanism for damping the large scale structure power spectrum. A combination of additional radiation and slightly damped structure is interesting because it can remove tensions between global $\\Lambda$CDM fits from the CMB and direct measurements of the Hubble expansion rate ($H_0$) and large scale structure ($\\sigma_8$).

  13. Dark matter axions

    E-Print Network [OSTI]

    P. Sikivie

    2009-09-04

    The hypothesis of an `invisible' axion was made by Misha Shifman and others, approximately thirty years ago. It has turned out to be an unusually fruitful idea, crossing boundaries between particle physics, astrophysics and cosmology. An axion with mass of order $10^{-5}$ eV (with large uncertainties) is one of the leading candidates for the dark matter of the universe. It was found recently that dark matter axions thermalize and form a Bose-Einstein condensate (BEC). Because they form a BEC, axions differ from ordinary cold dark matter (CDM) in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles. Because there is evidence for these phenomena, unexplained with ordinary CDM, an argument can be made that the dark matter is axions.

  14. Dissipation of dark matter

    E-Print Network [OSTI]

    Hermano Velten; Dominik J. Schwarz

    2012-10-01

    Fluids often display dissipative properties. We explore dissipation in the form of bulk viscosity in the cold dark matter fluid. We constrain this model using current data from supernovae, baryon acoustic oscillations and the cosmic microwave background. Considering the isotropic and homogeneous background only, viscous dark matter is allowed to have a bulk viscosity $\\lesssim 10^7$ Pa$\\cdot$s, also consistent with the expected integrated Sachs-Wolfe effect (which plagues some models with bulk viscosity). We further investigate the small-scale formation of viscous dark matter halos, which turns out to place significantly stronger constraints on the dark matter viscosity. The existence of dwarf galaxies is guaranteed only for much smaller values of the dark matter viscosity, $\\lesssim 10^{-3}$ Pa$\\cdot$s.

  15. Dark Energy and Dark Matter Models

    E-Print Network [OSTI]

    Burra G. Sidharth

    2015-08-27

    We revisit the problems of dark energy and dark matter and several models designed to explain them, in the light of some latest findings.

  16. Dark Energy and Dark Matter Models

    E-Print Network [OSTI]

    Burra G. Sidharth

    2015-11-30

    We revisit the problems of dark energy and dark matter and several models designed to explain them, in the light of some latest findings.

  17. Working Group Report: Dark Matter Complementarity (Dark Matter in the Coming Decade: Complementary Paths to Discovery and Beyond)

    SciTech Connect (OSTI)

    Arrenberg, Sebastian; et al.,

    2013-10-31

    In this Report we discuss the four complementary searches for the identity of dark matter: direct detection experiments that look for dark matter interacting in the lab, indirect detection experiments that connect lab signals to dark matter in our own and other galaxies, collider experiments that elucidate the particle properties of dark matter, and astrophysical probes sensitive to non-gravitational interactions of dark matter. The complementarity among the different dark matter searches is discussed qualitatively and illustrated quantitatively in several theoretical scenarios. Our primary conclusion is that the diversity of possible dark matter candidates requires a balanced program based on all four of those approaches.

  18. The search for TeV-scale dark matter with the HAWC observatory

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Harding, J. Patrick

    2015-01-01

    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to 100 GeV - 100 TeV gamma rays and cosmic rays. Located at an elevation of 4100 m on the Sierra Negra mountain in Mexico, HAWC observes extensive air showers from gamma and cosmic rays with an array of water tanks which produce Cherenkov light in the presence of air showers. With a field-of-view capable of observing 2/3 of the sky each day, and a sensitivity of 1 Crab/day, HAWC will be able to map out the sky in gamma and cosmic rays in detail. In thismore »paper, we discuss the capabilities of HAWC to map out the directions and spectra of TeV gamma rays and cosmic rays coming from sources of dark matter annihilation. We discuss the HAWC sensitivity to multiple extended sources of dark matter annihilation and the possibility of HAWC observations of annihilations in nearby dark matter subhalos.« less

  19. The search for TeV-scale dark matter with the HAWC observatory

    SciTech Connect (OSTI)

    Harding, J. Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-01

    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to 100 GeV - 100 TeV gamma rays and cosmic rays. Located at an elevation of 4100 m on the Sierra Negra mountain in Mexico, HAWC observes extensive air showers from gamma and cosmic rays with an array of water tanks which produce Cherenkov light in the presence of air showers. With a field-of-view capable of observing 2/3 of the sky each day, and a sensitivity of 1 Crab/day, HAWC will be able to map out the sky in gamma and cosmic rays in detail. In this paper, we discuss the capabilities of HAWC to map out the directions and spectra of TeV gamma rays and cosmic rays coming from sources of dark matter annihilation. We discuss the HAWC sensitivity to multiple extended sources of dark matter annihilation and the possibility of HAWC observations of annihilations in nearby dark matter subhalos.

  20. Fits to the Fermi-LAT GeV excess with RH sneutrino dark matter: implications for direct and indirect dark matter searches and the LHC

    E-Print Network [OSTI]

    Cerdeno, D G; Robles, S

    2015-01-01

    We show that the right-handed (RH) sneutrino in the NMSSM can account for the observed excess in the Fermi-LAT spectrum of gamma rays from the Galactic Centre, while fulfilling all the current experimental constraints from the LHC as well as from direct and indirect dark matter searches. We have explored the parameter space of this scenario, computed the gamma ray spectrum for each phenomenologically viable solution and then performed a chi^2 fit to the excess. Unlike previous studies based on model independent interpretations, we have taken into account the full annihilation spectrum, without assuming pure annihilation channels. Furthermore, we have incorporated limits from direct detection experiments, LHC bounds and also the constraints from Fermi-LAT on dwarf spheroidal galaxies (dSphs) and gamma ray spectral lines. In addition, we have estimated the effect of the most recent Fermi-LAT reprocessed data (Pass~8). In general, we obtain good fits to the GCE when the RH sneutrino annihilates mainly into pairs...

  1. Baryon Destruction by Asymmetric Dark Matter

    E-Print Network [OSTI]

    Hooman Davoudiasl; David E. Morrissey; Kris Sigurdson; Sean Tulin

    2011-06-21

    We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause {\\it induced nucleon decay} by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 10^{29}-10^{32} years in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter--induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.

  2. Baryon Destruction by Asymmetric Dark Matter

    E-Print Network [OSTI]

    Davoudiasl, Hooman; Sigurdson, Kris; Tulin, Sean

    2011-01-01

    We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause {\\it induced nucleon decay} by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 10^{29}-10^{32} years in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter--induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.

  3. Search for a Dark Matter Candidate Produced in Association with a Single Top Quark in pp? Collisions at ?s=1.96 TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Anzá, F.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calamba, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chung, W. H.; Chung, Y. S.; Ciocci, M. A.; Clark, A.; Clarke, C.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; d’Ascenzo, N.; Datta, M.; de Barbaro, P.; Dell’Orso, M.; Demortier, L.; Deninno, M.; Devoto, F.; d’Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D’Onofrio, M.; Donati, S.; Dong, P.; Dorigo, M.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, S.; Ershaidat, N.; Eusebi, R.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Fuks, B.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Klimenko, S.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lin, C.-J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martínez, M.; Mastrandrea, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.

    2012-05-01

    We report a new search for dark matter in a data sample of an integrated luminosity of 7.7 fb?¹ of Tevatron pp¯ collisions at ?s=1.96 TeV, collected by the CDF II detector. We search for production of a dark-matter candidate, D, in association with a single top quark. We consider the hadronic decay mode of the top quark exclusively, yielding a final state of three jets with missing transverse energy. The data are consistent with the standard model; we thus set 95% confidence level upper limits on the cross section of the process pp??t+D as a function of the mass of the dark-matter candidate. The limits are approximately 0.5 pb for a dark-matter particle with mass in the range of 0–150 GeV/c².

  4. Search for a Dark Matter Candidate Produced in Association with a Single Top Quark in pp? Collisions at ?s=1.96 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Anzá, F.; Apollinari, G.; Appel, J. A.; et al

    2012-05-01

    We report a new search for dark matter in a data sample of an integrated luminosity of 7.7 fb?¹ of Tevatron pp¯ collisions at ?s=1.96 TeV, collected by the CDF II detector. We search for production of a dark-matter candidate, D, in association with a single top quark. We consider the hadronic decay mode of the top quark exclusively, yielding a final state of three jets with missing transverse energy. The data are consistent with the standard model; we thus set 95% confidence level upper limits on the cross section of the process pp??t+D as a function of the massmore »of the dark-matter candidate. The limits are approximately 0.5 pb for a dark-matter particle with mass in the range of 0–150 GeV/c².« less

  5. Axion BEC Dark Matter

    E-Print Network [OSTI]

    Erken, Ozgur; Tam, Heywood; Yang, Qiaoli

    2011-01-01

    Cold dark matter axions thermalize through gravitational self-interactions and form a Bose-Einstein condensate when the photon temperature reaches approximately 500 eV. Axion Bose-Einstein condensation provides an opportunity to distinguish axions from the other dark matter candidates on the basis of observation. The rethermalization of axions that are about to fall in a galactic potential well causes them to acquire net overall rotation, whereas ordinary cold dark matter falls in with an irrotational velocity field. The inner caustics of galactic halos are different in the two cases.

  6. Axion BEC Dark Matter

    E-Print Network [OSTI]

    Ozgur Erken; Pierre Sikivie; Heywood Tam; Qiaoli Yang

    2011-11-16

    Cold dark matter axions thermalize through gravitational self-interactions and form a Bose-Einstein condensate when the photon temperature reaches approximately 500 eV. Axion Bose-Einstein condensation provides an opportunity to distinguish axions from the other dark matter candidates on the basis of observation. The rethermalization of axions that are about to fall in a galactic potential well causes them to acquire net overall rotation, whereas ordinary cold dark matter falls in with an irrotational velocity field. The inner caustics of galactic halos are different in the two cases.

  7. First measurement of the Head-Tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches

    E-Print Network [OSTI]

    S. Burgos; E. Daw; J. Forbes; C. Ghag; M. Gold; C. Hagemann; V. A. Kudryavtsev; T. B. Lawson; D. Loomba; P. Majewski; D. Muna; A. StJ. Murphy; G. G. Nicklin; S. M. Paling; A. Petkov; S. J. S. Plank; M. Robinson; N. Sanghi; D. P. Snowden-Ifft; N. J. C. Spooner; J. Turk; E. Tziaferi

    2008-09-10

    We present first evidence for the so-called Head-Tail asymmetry signature of neutron-induced nuclear recoil tracks at energies down to 1.5 keV/amu using the 1m^3 DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here by Cf-252 neutrons matches well that expected from massive WIMPs. The results open a powerful new means of searching for a galactic signature from WIMPs.

  8. The DAMIC dark matter experiment

    E-Print Network [OSTI]

    Aguilar-Arevalo, A; Bertou, X; Bole, D; Butner, M; Cancelo, G; Vázquez, A Castañeda; Chavarria, A E; Neto, J R T de Mello; Dixon, S; D'Olivo, J C; Estrada, J; Moroni, G Fernandez; Torres, K P Hernández; Izraelevitch, F; Kavner, A; Kilminster, B; Lawson, I; Liao, J; López, M; Molina, J; Moreno-Granados, G; Pena, J; Privitera, P; Sarkis, Y; Scarpine, V; Schwarz, T; Haro, M Sofo; Tiffenberg, J; Machado, D Torres; Trillaud, F; You, X; Zhou, J

    2015-01-01

    The DAMIC (Dark Matter in CCDs) experiment uses high resistivity, scientific grade CCDs to search for dark matter. The CCD's low electronic noise allows an unprecedently low energy threshold of a few tens of eV that make it possible to detect silicon recoils resulting from interactions of low mass WIMPs. In addition the CCD's high spatial resolution and the excellent energy response results in very effective background identification techniques. The experiment has a unique sensitivity to dark matter particles with masses below 10 GeV/c$^2$. Previous results have demonstrated the potential of this technology, motivating the construction of DAMIC100, a 100 grams silicon target detector currently being installed at SNOLAB. In this contribution, the mode of operation and unique imaging capabilities of the CCDs, and how they may be exploited to characterize and suppress backgrounds will be discussed, as well as physics results after one year of data taking.

  9. Flavored dark matter beyond minimal flavor violation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Agrawal, Prateek; Blanke, Monika; Gemmler, Katrin

    2014-10-13

    We study the interplay of flavor and dark matter phenomenology for models of flavored dark matter interacting with quarks. We allow an arbitrary flavor structure in the coupling of dark matter with quarks. This coupling is assumed to be the only new source of violation of the Standard Model flavor symmetry extended by a U(3)x associated with the dark matter. We call this ansatz Dark Minimal Flavor Violation (DMFV) and highlight its various implications, including an unbroken discrete symmetry that can stabilize the dark matter. As an illustration we study a Dirac fermionic dark matter ? which transforms asmore »triplet under U(3)x , and is a singlet under the Standard Model. The dark matter couples to right-handed down-type quarks via a colored scalar mediator ? with a coupling ?. We identify a number of “flavor-safe” scenarios for the structure of ? which are beyond Minimal Flavor Violation. For dark matter and collider phenomenology we focus on the well-motivated case of b-flavored dark matter. The combined flavor and dark matter constraints on the parameter space of ? turn out to be interesting intersections of the individual ones. LHC constraints on simplified models of squarks and sbottoms can be adapted to our case, and monojet searches can be relevant if the spectrum is compressed.« less

  10. Search for a Dark Matter Candidate Produced in Association with a Single Top Quark in pp? Collisions at ?s=1.96??TeV

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    We report a new search for dark matter in a data sample of an integrated luminosity of 7.7??fb[superscript -1] of Tevatron pp? collisions at ?s=1.96??TeV, collected by the CDF II detector. We search for production of a ...

  11. Non-Abelian dark matter and dark radiation

    E-Print Network [OSTI]

    Buen-Abad, Manuel A; Schmaltz, Martin

    2015-01-01

    We propose a new class of dark matter models with unusual phenomenology. What is ordinary about our models is that dark matter particles are WIMPs, they are weakly coupled to the Standard Model and have weak scale masses. What is unusual is that they come in multiplets of a new "dark" non-Abelian gauge group with milli-weak coupling. The massless dark gluons of this dark gauge group contribute to the energy density of the universe as a form of weakly self-interacting dark radiation. In this paper we explore the consequences of having i.) dark matter in multiplets ii.) self-interacting dark radiation and iii.) dark matter which is weakly coupled to dark radiation. We find that i.) dark matter cross sections are modified by multiplicity factors which have significant consequences for collider searches and indirect detection, ii.) dark gluons have thermal abundances which affect the CMB as dark radiation. Unlike additional massless neutrino species the dark gluons are interacting and have vanishing viscosity and...

  12. Gaseous dark matter detectors

    E-Print Network [OSTI]

    Martoff, C. J.

    Dark matter (DM) detectors with directional sensitivity have the potential of yielding an unambiguous positive observation of WIMPs as well as discriminating between galactic DM halo models. In this paper, we introduce the ...

  13. Hot and dark matter

    E-Print Network [OSTI]

    D'Eramo, Francesco

    2012-01-01

    In this thesis, we build new Effective Field Theory tools to describe the propagation of energetic partons in hot and dense media, and we propose two new reactions for dark matter in the early universe. In the first part, ...

  14. A fussy revisitation of antiprotons as a tool for Dark Matter searches

    E-Print Network [OSTI]

    Mathieu Boudaud; Marco Cirelli; Gaëlle Giesen; Pierre Salati

    2015-03-16

    Antiprotons are regarded as a powerful probe for Dark Matter (DM) indirect detection and indeed current data from PAMELA have been shown to lead to stringent constraints. However, in order to exploit their constraining/discovery power properly and especially in anticipation of the exquisite accuracy of upcoming data from AMS, great attention must be put into effects (linked to their propagation in the Galaxy) which may be perceived as subleasing but actually prove to be quite relevant. We revisit the computation of the astrophysical background and of the DM antiproton fluxes fully including the effects of: diffusive reacceleration, energy losses including tertiary component and solar modulation (in a force field approximation). We show that their inclusion can somewhat modify the current bounds, even at large DM masses, and that a wrong interpretation of the data may arise if they are not taken into account. The numerical results for the astrophysical background are provided in terms of fit functions; the results for Dark Matter are incorporated in the new release of the PPPC4DMID.

  15. Searches for Dark Matter at the LHC: A Multivariate Analysis in the Mono-$Z$ Channel

    E-Print Network [OSTI]

    Alexandre Alves; Kuver Sinha

    2015-07-29

    We study dark matter (DM) production in the mono-Z channel at the 13 TeV LHC both in an effective field theory framework as well as in simplified models with vector mediators, using a multivariate analysis. For DM-quark effective operators with scalar, vector, and tensor couplings and DM mass of 100 GeV, the 5$\\sigma$ reach in the DM interaction scale $\\Lambda$ is around 2, 1, and 3 TeV, respectively, for 3 ab$^{-1}$ and assuming a 5\\% systematic uncertainty on the total background normalization. For simplified models with leptophobic vector mediators, the 5$\\sigma$ reach for the mass of the mediator is 1.7 TeV also assuming a 5\\% systematics and 3 ab$^{-1}$ of integrated luminosity. The reach for the dark matter interaction scale obtained with the multivariate analysis using a likelihood function discriminant is at least twice as high as that obtained from a simple cut and count analysis, once systematics on the background normalization larger than a few percent are taken into account. Moreover, the reach is much more stable against degradation due these systematic uncertainties.

  16. Searches for Dark Matter at the LHC: A Multivariate Analysis in the Mono-$Z$ Channel

    E-Print Network [OSTI]

    Alves, Alexandre

    2015-01-01

    We study dark matter (DM) production in the mono-Z channel at the 13 TeV LHC both in an effective field theory framework as well as in simplified models with vector mediators, using a multivariate analysis. For DM-quark effective operators with scalar, vector, and tensor couplings and DM mass of 100 GeV, the 5$\\sigma$ reach in the DM interaction scale $\\Lambda$ is around 2, 1, and 3 TeV, respectively, for 3 ab$^{-1}$ and assuming a 5\\% systematic uncertainty on the total background normalization. For simplified models with leptophobic vector mediators, the 5$\\sigma$ reach for the mass of the mediator is 1.7 TeV also assuming a 5\\% systematics and 3 ab$^{-1}$ of integrated luminosity. The reach for the dark matter interaction scale obtained with the multivariate analysis using a likelihood function discriminant is at least twice as high as that obtained from a simple cut and count analysis, once systematics on the background normalization larger than a few percent are taken into account. Moreover, the reach is...

  17. Impact of nucleon matrix element uncertainties on the interpretation of direct and indirect dark matter search results

    SciTech Connect (OSTI)

    Austri, R. Ruiz de

    2013-11-01

    We study in detail the impact of the current uncertainty in nucleon matrix elements on the sensitivity of direct and indirect experimental techniques for dark matter detection. We perform two scans in the framework of the cMSSM: one using recent values of the pion-sigma term obtained from Lattice QCD, and the other using values derived from experimental measurements. The two choices correspond to extreme values quoted in the literature and reflect the current tension between different ways of obtaining information about the structure of the nucleon. All other inputs in the scans, astrophysical and from particle physics, are kept unchanged. We use two experiments, XENON100 and IceCube, as benchmark cases to illustrate our case. We find that the interpretation of dark matter search results from direct detection experiments is more sensitive to the choice of the central values of the hadronic inputs than the results of indirect search experiments. The allowed regions of cMSSM parameter space after including XENON100 constraints strongly differ depending on the assumptions on the hadronic matrix elements used. On the other hand, the constraining potential of IceCube is almost independent of the choice of these values.

  18. Low-scale seesaw and dark matter

    E-Print Network [OSTI]

    M. Fabbrichesi; S. Petcov

    2013-04-15

    We discuss how two birds---the little hierarchy problem of low-scale type-I seesaw models and the search for a viable dark matter candidate---are (proverbially) killed by one stone: a new inert scalar state

  19. The C-4 Dark Matter Experiment

    SciTech Connect (OSTI)

    Bonicalzi, Ricco; Collar, J. I.; Colaresi, J.; Fast, James E.; Fields, N.; Fuller, Erin S.; Hai, M.; Hossbach, Todd W.; Kos, Marek S.; Orrell, John L.; Overman, Cory T.; Reid, Douglas J.; VanDevender, Brent A.; Wiseman, Clinton G.; Yocum, K. M.

    2013-06-01

    Abstract We describe the experimental design of C-4, an expansion of the CoGeNT dark matter search to four identical detectors each approximately three times the mass of the p-type point contact (PPC) germanium diode presently taking data at the Soudan Underground Laboratory. Expected reductions of radioactive backgrounds and energy threshold are discussed, including an estimate of the additional sensitivity to low-mass dark matter candidates to be obtained with this search.

  20. Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp? Collisions at ?s=1.96 TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Bai, Y.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calamba, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chung, W. H.; Chung, Y. S.; Ciocci, M. A.; Clark, A.; Clarke, C.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; d’Ascenzo, N.; Datta, M.; de Barbaro, P.; Dell’Orso, M.; Demortier, L.; Deninno, M.; Devoto, F.; d’Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D’Onofrio, M.; Donati, S.; Dong, P.; Dorigo, M.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, S.; Ershaidat, N.; Eusebi, R.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Fox, P. J.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harnik, R.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Klimenko, S.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lin, C.-J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martínez, M.; Mastrandrea, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.

    2012-05-01

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp? collisions at ?s=1.96 TeV corresponding to an integrated luminosity of 6.7 fb?¹ recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c², and on spin-dependent interactions up to masses of 200 GeV/c².

  1. Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp? Collisions at ?s=1.96 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; et al

    2012-05-23

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp? collisions at ?s=1.96 TeV corresponding to an integrated luminosity of 6.7 fb?¹ recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction belowmore »a dark matter candidate mass of 5 GeV/c², and on spin-dependent interactions up to masses of 200 GeV/c².« less

  2. Early search for supersymmetric dark matter models at the LHC without missing energy

    E-Print Network [OSTI]

    Joakim Edsjo; Erik Lundstrom; Sara Rydbeck; Jorgen Sjolin

    2010-03-13

    We investigate early discovery signals for supersymmetry at the Large Hadron Collider without using information about missing transverse energy. Instead we use cuts on the number of jets and isolated leptons (electrons and/or muons). We work with minimal supersymmetric extensions of the standard model, and focus on phenomenological models that give a relic density of dark matter compatible with the WMAP measurements. An important model property for early discovery is the presence of light sleptons, and we find that for an integrated luminosity of only 200--300 pb$^{-1}$ at a center-of-mass energy of 10 TeV models with gluino masses up to $\\sim 700$ GeV can be tested.

  3. A fussy revisitation of antiprotons as a tool for Dark Matter searches

    E-Print Network [OSTI]

    Boudaud, Mathieu

    2015-01-01

    Antiprotons are regarded as a powerful probe for Dark Matter (DM) indirect detection and indeed current data from \\PAMELA\\ have been shown to lead to stringent constraints. However, in order to exploit their constraining/discovery power properly, great attention must be put into effects (linked to their propagation in the Galaxy) which may be perceived as subleading but actually prove to be quite relevant. We revisit the computation of the astrophysical background and of the DM antiproton fluxes fully including the effects of: diffusive reacceleration, energy losses including tertiary component and solar modulation (in a force field approximation). Using the updated proton and helium fluxes just released by the \\AMS\\ experiment we reevaluate the secondary astrophysical antiproton to proton ratio and its uncertainties, and compare it with the ratio preliminarly reported by \\AMS. We find no unambiguous evidence for a significant excess with respect to expectations. Yet, some preference for a flatter energy depe...

  4. Levitating Dark Matter

    E-Print Network [OSTI]

    Nemanja Kaloper; Antonio Padilla

    2009-10-07

    A sizable fraction of the total energy density of the universe may be in heavy particles with a net dark $U(1)'$ charge comparable to its mass. When the charges have the same sign the cancellation between their gravitational and gauge forces may lead to a mismatch between different measures of masses in the universe. Measuring galactic masses by orbits of normal matter, such as galaxy rotation curves or lensing, will give the total mass, while the flows of dark matter agglomerates may yield smaller values if the gauge repulsion is not accounted for. If distant galaxies which house light beacons like SNe Ia contain such dark particles, the observations of their cosmic recession may mistake the weaker forces for an extra `antigravity', and infer an effective dark energy equation of state smaller than the real one. In some cases, including that of a cosmological constant, these effects can mimic $wdark energy, or superhorizon effects.

  5. Natural minimal dark matter

    E-Print Network [OSTI]

    Fabbrichesi, Marco

    2015-01-01

    We show how the Higgs boson mass is protected from the potentially large corrections due to the introduction of minimal dark matter if the new physics sector is made supersymmetric. The fermionic dark matter candidate (a 5-plet of $SU(2)_L$) is accompanied by a scalar state. The weak gauge sector is made supersymmetric and the Higgs boson is embedded in a supersymmetric multiplet. The remaining standard model states are non-supersymmetric. Non vanishing corrections to the Higgs boson mass only appear at three-loop level and the model is natural for dark matter masses up to 15 TeV--a value larger than the one required by the cosmological relic density. The construction presented stands as an example of a general approach to naturalness that solves the little hierarchy problem which arises when new physics is added beyond the standard model at an energy scale around 10 TeV.

  6. Dark matter from decaying topological defects

    SciTech Connect (OSTI)

    Hindmarsh, Mark [Helsinki Institute of Physics, Gustaf Hällströmin katu, P.O. Box 64, 00014 Helsinki University (Finland); Kirk, Russell; West, Stephen M., E-mail: m.b.hindmarsh@sussex.ac.uk, E-mail: russell.kirk.2008@live.rhul.ac.uk, E-mail: stephen.west@rhul.ac.uk [Dept. of Physics, Royal Holloway University of London, Egham Hill, Egham, Surrey, TW20 0EX (United Kingdom)

    2014-03-01

    We study dark matter production by decaying topological defects, in particular cosmic strings. In topological defect or ''top-down'' (TD) scenarios, the dark matter injection rate varies as a power law with time with exponent p?4. We find a formula in closed form for the yield for all p < 3/2, which accurately reproduces the solution of the Boltzmann equation. We investigate two scenarios (p = 1, p = 7/6) motivated by cosmic strings which decay into TeV-scale states with a high branching fraction into dark matter particles. For dark matter models annihilating either by s-wave or p-wave, we find the regions of parameter space where the TD model can account for the dark matter relic density as measured by Planck. We find that topological defects can be the principal source of dark matter, even when the standard freeze-out calculation under-predicts the relic density and hence can lead to potentially large ''boost factor'' enhancements in the dark matter annihilation rate. We examine dark matter model-independent limits on this scenario arising from unitarity and discuss example model-dependent limits coming from indirect dark matter search experiments. In the four cases studied, the upper bound on G? for strings with an appreciable channel into TeV-scale states is significantly more stringent than the current Cosmic Microwave Background limits.

  7. Wino dark matter under siege

    SciTech Connect (OSTI)

    Cohen, Timothy; Lisanti, Mariangela; Pierce, Aaron; Slatyer, Tracy R. E-mail: mlisanti@princeton.edu E-mail: tslatyer@mit.edu

    2013-10-01

    A fermion triplet of SU(2){sub L} — a wino — is a well-motivated dark matter candidate. This work shows that present-day wino annihilations are constrained by indirect detection experiments, with the strongest limits coming from H.E.S.S. and Fermi. The bounds on wino dark matter are presented as a function of mass for two scenarios: thermal (winos constitute a subdominant component of the dark matter for masses less than 3.1 TeV) and non-thermal (winos comprise all the dark matter). Assuming the NFW halo model, the H.E.S.S. search for gamma-ray lines excludes the 3.1 TeV thermal wino; the combined H.E.S.S. and Fermi results completely exclude the non-thermal scenario. Uncertainties in the exclusions are explored. Indirect detection may provide the only probe for models of anomaly plus gravity mediation where the wino is the lightest superpartner and scalars reside at the 100 TeV scale.

  8. Low Mass Neutralino Dark Matter in the MSSM with Constraints from $B_s\\to ?^+?^-$ and Higgs Search Limits

    E-Print Network [OSTI]

    Daniel Feldman; Zuowei Liu; Pran Nath

    2010-05-21

    The region of low neutralino masses as low as (5-10) GeV has attracted attention recently due to the possibility of excess events above background in dark matter detectors. An analysis of spin independent neutralino-proton cross sections $\\SI$ which includes this low mass region is given. The analysis is done in MSSM with radiative electroweak symmetry breaking (REWSB). It is found that cross sections as large as $10^{-40}$ cm$^2$ can be accommodated in MSSM within the REWSB framework. However, inclusion of sparticle mass limits from current experiments, as well as lower limits on the Higgs searches from the Tevatron, and the current experimental upper limit on $B_s\\to \\mu^+\\mu^-$ significantly limit the allowed parameter space reducing $\\SI$ to lie below $\\sim 10^{-41}$cm$^2$ or even lower for neutralino masses around 10 GeV. These cross sections are an order of magnitude lower than the cross sections needed to explain the reported data in the recent dark matter experiments in the low neutralino mass region.

  9. Dark galactic halos without dark matter

    E-Print Network [OSTI]

    R. K. Nesbet

    2015-03-03

    Using standard Einstein theory, baryonic mass cannot account for observed galactic rotation velocities and gravitational lensing, attributed to galactic dark matter halos. In contrast, theory constrained by Weyl conformal scaling symmetry explains observed galactic rotation in the halo region without invoking dark matter. An explanation of dark halos, gravitational lensing, and structural stabilization, without dark matter and consistent with conformal theory, is proposed here. Condensation of uniform primordial matter into a material cloud or galaxy vacates a large surrounding spherical halo. Within such an extended vacancy in the original cosmic background mass-energy density, conformal theory predicts centripetal acceleration of the observed magnitude.

  10. Dissipative hidden sector dark matter

    E-Print Network [OSTI]

    R. Foot; S. Vagnozzi

    2014-12-15

    A simple way of explaining dark matter without modifying known Standard Model physics is to require the existence of a hidden (dark) sector, which interacts with the visible one predominantly via gravity. We consider a hidden sector containing two stable particles charged under an unbroken $U(1)^{'}$ gauge symmetry, hence featuring dissipative interactions. The massless gauge field associated with this symmetry, the dark photon, can interact via kinetic mixing with the ordinary photon. In fact, such an interaction of strength $\\epsilon \\sim 10 ^{-9}$ appears to be necessary in order to explain galactic structure. We calculate the effect of this new physics on Big Bang Nucleosynthesis and its contribution to the relativistic energy density at Hydrogen recombination. We then examine the process of dark recombination, during which neutral dark states are formed, which is important for large-scale structure formation. Galactic structure is considered next, focussing on spiral and irregular galaxies. For these galaxies we modelled the dark matter halo (at the current epoch) as a dissipative plasma of dark matter particles, where the energy lost due to dissipation is compensated by the energy produced from ordinary supernovae (the core-collapse energy is transferred to the hidden sector via kinetic mixing induced processes in the supernova core). We find that such a dynamical halo model can reproduce several observed features of disk galaxies, including the cored density profile and the Tully-Fisher relation. We also discuss how elliptical and dwarf spheroidal galaxies could fit into this picture. Finally, these analyses are combined to set bounds on the parameter space of our model, which can serve as a guideline for future experimental searches.

  11. Anisotropic diffusion of electrons in liquid xenon with application to improving the sensitivity of direct dark matter searches

    SciTech Connect (OSTI)

    Sorensen, P

    2011-02-14

    Electron diffusion in a liquid xenon time projection chamber has recently been used to infer the z coordinate of a particle interaction, from the width of the electron signal. The goal of this technique is to reduce the background event rate by discriminating edge events from bulk events. Analyses of dark matter search data which employ it would benefit from increased longitudinal electron diffusion. We show that a significant increase is expected if the applied electric field is decreased. This observation is trivial to implement but runs contrary to conventional wisdom and practice. We also extract a first measurement of the longitudinal diffusion coefficient, and confirm the expectation that electron diffusion in liquid xenon is highly anisotropic under typical operating conditions.

  12. First results from a Dark Matter search with liquid Argon at 87 K in the Gran Sasso Underground Laboratory

    E-Print Network [OSTI]

    Benetti, P; Adamo, F; Baibussinov, B; Baldo-Ceolin, M; Belluco, M; Calaprice, F; Calligarich, E; Cambiaghi, M; Carbonara, F; Cavanna, F; Centro, Sandro; Cocco, A G; Di Pompeo, F; Ferrari, N; Fiorillo, G; Galbiati, C; Gallo, V; Grandi, L; Ianni, A; Mangano, G; Meng, G; Montanari, C; Palamara, O; Pandola, L; Pietropaolo, F; Raselli, G L; Rossella, M; Rubbia, C; Szelc, A M; Ventura, Sandro; Vignoli, C; 10.1016/j.astropartphys.2007.08.002

    2008-01-01

    A new method of searching for dark matter in the form of weakly interacting massive particles (WIMP) has been developed with the direct detection of the low energy nuclear recoils observed in a massive target (ultimately many tons) of ultra pure Liquid Argon at 87 K. A high selectivity for Argon recoils is achieved by the simultaneous observation of both the VUV scintillation luminescence and of the electron signal surviving columnar recombination, extracted through the liquid-gas boundary by an electric field. First physics results from this method are reported, based on a small 2.3 litre test chamber filled with natural Argon and an accumulated fiducial exposure of about 100 kg x day, supporting the future validity of this method with isotopically purified 40Ar and for a much larger unit presently under construction with correspondingly increased sensitivities.

  13. Detecting the invisible universe with neutrinos and dark matter

    E-Print Network [OSTI]

    Kaboth, Asher C. (Asher Cunningham)

    2012-01-01

    Recent work in astrophysics has show that most of the matter in the universe is non-luminous. This work investigates two searches for non-luminous matter: hot dark matter formed from cosmic relic neutrinos from the Big ...

  14. Search for Dark Matter in Events with a Z Boson and Missing Transverse Momentum in pp Collisions at ?s = 8 TeV with the ATLAS Detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search is presented for production of dark-matter particles recoiling against a leptonically decaying Z boson in 20.3??fb[superscript ?1] of pp collisions at ?s = 8??TeV with the ATLAS detector at the Large Hadron Collider. ...

  15. Search for Dark Matter in Events with One Jet and Missing Transverse Energy in pp? Collisions at ?s=1.96??TeV

    E-Print Network [OSTI]

    Gomez-Ceballos, Guillelmo

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp? collisions at ?s=1.96??TeV corresponding to an integrated luminosity of 6.7??fb[superscript -1] ...

  16. Dark Matter Studies Entrain Nuclear Physics

    E-Print Network [OSTI]

    Susan Gardner; George Fuller

    2013-03-19

    We review theoretically well-motivated dark-matter candidates, and pathways to their discovery, in the light of recent results from collider physics, astrophysics, and cosmology. Taken in aggregate, these encourage broader thinking in regards to possible dark-matter candidates --- dark-matter need not be made of "WIMPs," i.e., elementary particles with weak-scale masses and interactions. Facilities dedicated to nuclear physics are well-poised to investigate certain non-WIMP models. In parallel to this, developments in observational cosmology permit probes of the relativistic energy density at early epochs and thus provide new ways to constrain dark-matter models, provided nuclear physics inputs are sufficiently well-known. The emerging confluence of accelerator, astrophysical, and cosmological constraints permit searches for dark-matter candidates in a greater range of masses and interaction strengths than heretofore possible.

  17. Measurement of scintillation and ionization yield with high-pressure gaseous mixtures of Xe and TMA for improved neutrinoless double beta decay and dark matter searches

    E-Print Network [OSTI]

    Nakajima, Y; Matis, H S; Nygren, D; Oliveira, C; Renner, J

    2015-01-01

    Liquid Xe TPCs are among the most popular choices for double beta decay and WIMP dark matter searches. Gaseous Xe has intrinsic advantages when compared to Liquid Xe, specifically, tracking capability and better energy resolution for double beta decay searches. The performance of gaseous Xe can be further improved by molecular additives such as trimethylamine(TMA), which are expected to (1) cool down the ionization electrons, (2) convert Xe excitation energy to TMA ionizations through Penning transfer, and (3) produce scintillation and electroluminescence light in a more easily detectable wavelength (300 nm). These features may provide better tracking and energy resolution for double-beta decay searches. They are also expected to enhance columnar recombination for nuclear recoils, which can be used for searches for WIMP dark matter with directional sensitivity. We constructed a test ionization chamber and successfully measured scintillation and ionization yields at high precision with various Xe and TMA mixtu...

  18. Searching for Dark Sector

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-ThroughputUpcomingmagnetoresistance |Komlov,Search / Search Search EnterDark Sector

  19. An indirect dark matter search with diffuse gamma rays from the Galactic Centre with the Alpha Magnetic Spectrometer

    E-Print Network [OSTI]

    A. Jacholkowska; G. Lamanna; E. Nuss; J. Bolmont; C. Adloff; J. Alcaraz; R. Battiston; P. Brun; W. J. Burger; V. Choutko; G. Coignet; A. Falvard; E. Flandrini; L. Girard; C. Goy; K. Jedamzik; R. Kossakowski; G. Moultaka; S. Natale; J. Pochon; M. Pohl; S. Rosier-Lees; M. Sapinski; I. Sevilla Noarbe; JP. Vialle

    2006-05-23

    The detection of non-baryonic dark matter through its gamma-ray annihilation in the centre of our galaxy has been studied. The gamma fluxes according to different models have been simulated and compared to those expected to be observed with the Alpha Magnetic Spectrometer (AMS), during a long-term mission on board of the International Space Station. Under the assumption that the dark matter halo is composed of the lightest, stable supersymmetric particle, the neutralino, the results of the simulations in the framework of mSUGRA models, show that with a cuspy dark matter halo or a clumpy halo, the annihilation gamma-ray signal would be detected by AMS. More optimistic perspectives are obtained with the Anomaly Mediated Supersymmetry Breaking (AMSB) model. The latter leads also to a cosmologically important 6Li abundance. Finally, the discovery potential for the massive Kaluza-Klein dark matter candidates has been evaluated and their detection looks feasible.

  20. Asymmetric condensed dark matter

    E-Print Network [OSTI]

    Aguirre, Anthony

    2015-01-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate can be very light, $10^{-22}\\,{\\rm eV} \\lesssim m \\lesssim 10^2\\,{\\rm eV}$; the lower limit arises from constraints on small-scale structure formation, while the upper bound ensures that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of deco...

  1. Tunguska Dark Matter Ball

    E-Print Network [OSTI]

    C. D. Froggatt; H. B. Nielsen

    2015-05-10

    It is suggested that the Tunguska event in June 1908 cm-large was due to a cm-large ball of a condensate of bound states of 6 top and 6 anti-top quarks containing highly compressed ordinary matter. Such balls are supposed to make up the dark matter as we earlier proposed. The expected rate of impact of this kind of dark matter ball with the earth seems to crudely match a time scale of 200 years between the impacts. The main explosion of the Tunguska event is explained in our picture as material coming out from deep within the earth, where it has been heated and compressed by the ball penetrating to a depth of several thousand km. Thus the effect has some similarity with volcanic activity as suggested by Kundt. We discuss the possible identification of kimberlite pipes with earlier Tunguska-like events. A discussion of how the dark matter balls may have formed in the early universe is also given.

  2. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab

    E-Print Network [OSTI]

    BDX Collaboration; M. Battaglieri; A. Celentano; R. De Vita; E. Izaguirre; G. Krnjaic; E. Smith; S. Stepanyan; A. Bersani; E. Fanchini; S. Fegan; P. Musico; M. Osipenko; M. Ripani; E. Santopinto; M. Taiuti; P. Schuster; N. Toro; M. Dalton; A. Freyberger; F. -X. Girod; V. Kubarovsky; M. Ungaro; G. De Cataldo; R. De Leo; D. Di Bari; L. Lagamba; E. Nappi; R. Perrino; M. Carpinelli; V. Sipala; S. Aiello; V. Bellini; M. De Napoli; A. Giusa; F. Mammoliti; E. Leonora; F. Noto; N. Randazzo; G. Russo; M. Sperduto; C. Sutera; C. Ventura; L. Barion; G. Ciullo; M. Contalbrigo; P. Lenisa; A. Movsisyan; F. Spizzo; M. Turisini; F. De Persio; E. Cisbani; C. Fanelli; F. Garibaldi; F. Meddi; G. M. Urciuoli; S. Anefalos Pereira; E. De Sanctis; D. Hasch; V. Lucherini; M. Mirazita; R. Montgomery; S. Pisano; G. Simi; A. D'Angelo; L. Colaneri L. Lanza; A. Rizzo; C. Schaerf; I. Zonta; D. Calvo; A. Filippi; M. Holtrop; R. Peremuzyan; D. Glazier; D. Ireland; B. McKinnon; D. Sokhan A. Afanasev; B. Briscoe; N. Kalantarians; L. El Fassi; L. Weinstein; P. Beltrame; A. Murphy; D. Watts; L. Zana; K. Hicks

    2014-06-11

    MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This Letter of Intent presents the MeV-GeV DM discovery potential for a 1 m$^3$ segmented plastic scintillator detector placed downstream of the beam-dump at one of the high intensity JLab experimental Halls, receiving up to 10$^{22}$ electrons-on-target (EOT) in a one-year period. This experiment (Beam-Dump eXperiment or BDX) is sensitive to DM-nucleon elastic scattering at the level of a thousand counts per year, with very low threshold recoil energies ($\\sim$1 MeV), and limited only by reducible cosmogenic backgrounds. Sensitivity to DM-electron elastic scattering and/or inelastic DM would be below 10 counts per year after requiring all electromagnetic showers in the detector to exceed a few-hundred MeV, which dramatically reduces or altogether eliminates all backgrounds. Detailed Monte Carlo simulations are in progress to finalize the detector design and experimental set up. An existing 0.036 m$^3$ prototype based on the same technology will be used to validate simulations with background rate estimates, driving the necessary R$\\&$D towards an optimized detector. The final detector design and experimental set up will be presented in a full proposal to be submitted to the next JLab PAC. A fully realized experiment would be sensitive to large regions of DM parameter space, exceeding the discovery potential of existing and planned experiments by two orders of magnitude in the MeV-GeV DM mass range.

  3. Directional detection of galactic dark matter

    E-Print Network [OSTI]

    Mayet, F; Santos, D

    2012-01-01

    Directional detection is a promising Dark Matter search strategy. Taking advantage on the rotation of the Solar system around the galactic center through the Dark Matter halo, it allows to show a direction dependence of WIMP events that may be a powerful tool to identify genuine WIMP events as such. Directional detection strategy requires the simultaneous measurement of the energy and the 3D track of low energy recoils, which is a common challenge for all current projects of directional detectors.

  4. First Results from the Cryogenic Dark Matter Search Experiment at the B.S. (California Institute of Technology)

    E-Print Network [OSTI]

    California at Berkeley, University of

    .S. (California Institute of Technology) A dissertation submitted in partial satisfaction of the requirements Contents List of Figures vii List of Tables xxiii 1 Introduction 1 1.1 Introduction for Existence of Dark Matter and Dark Energy . . . . . . . . . . . 7 1.3.1 Spiral Galaxies

  5. Dark Matter Detectors as Dark Photon Helioscopes

    E-Print Network [OSTI]

    Haipeng An; Maxim Pospelov; Josef Pradler

    2013-08-20

    Light new particles with masses below 10 keV, often considered as a plausible extension of the Standard Model, will be emitted from the solar interior, and can be detected on the Earth with a variety of experimental tools. Here we analyze the new "dark" vector state V, a massive vector boson mixed with the photon via an angle kappa, that in the limit of the small mass m_V has its emission spectrum strongly peaked at low energies. Thus, we utilize the constraints on the atomic ionization rate imposed by the results of the XENON10 experiment to set the limit on the parameters of this model: kappa times m_VeV. This makes low-threshold Dark Matter experiments the most sensitive dark vector helioscopes, as our result not only improves current experimental bounds from other searches by several orders of magnitude, but also surpasses even the most stringent astrophysical and cosmological limits in a seven-decade-wide interval of m_V. We generalize this approach to other light exotic particles, and set the most stringent direct constraints on "mini-charged" particles.

  6. Hidden vector dark matter

    E-Print Network [OSTI]

    Thomas Hambye

    2010-03-16

    We show that dark matter could be made of massive gauge bosons whose stability doesn't require to impose by hand any discrete or global symmetry. Stability of gauge bosons can be guaranteed by the custodial symmetry associated to the gauge symmetry and particle content of the model. The particle content we consider to this end is based on a hidden sector made of a vector multiplet associated to a non-abelian gauge group and of a scalar multiplet charged under this gauge group. The hidden sector interacts with the Standard Model particles through the Higgs portal quartic scalar interaction in such a way that the gauge bosons behave as thermal WIMPS. This can lead easily to the observed dark matter relic density in agreement with the other various constraints, and can be tested experimentally in a large fraction of the parameter space. In this model the dark matter direct detection rate and the annihilation cross section can decouple if the Higgs portal interaction is weak.

  7. Coupling dark energy to dark matter perturbations

    E-Print Network [OSTI]

    Valerio Marra

    2015-06-21

    This Letter proposes that dark energy in the form of a scalar field could effectively couple to dark matter perturbations. The idea is that dark matter particles could annihilate/interact inside dense clumps and transfer energy to the scalar field, which would then enter an accelerated regime. This hypothesis is interesting as it provides a natural trigger for the onset of the acceleration of the universe, since dark energy starts driving the expansion of the universe when matter perturbations become sufficiently dense. Here we study a possible realization of this general idea by coupling dark energy to dark matter via the linear growth function of matter perturbations. The numerical results show that it is indeed possible to obtain a viable cosmology with the expected series of radiation, matter and dark-energy dominated eras. Moreover, the current density of dark energy is given by the value of the coupling parameters rather than by very special initial conditions for the scalar field. In other words, this model does not suffer from the so-called "coincidence problem" and its related fine tuning of initial conditions.

  8. Coupling dark energy to dark matter perturbations

    E-Print Network [OSTI]

    Marra, Valerio

    2015-01-01

    This Letter proposes that dark energy in the form of a scalar field could effectively couple to dark matter perturbations. The idea is that dark matter particles could annihilate/interact inside dense clumps and transfer energy to the scalar field, which would then enter an accelerated regime. This hypothesis is interesting as it provides a natural trigger for the onset of the acceleration of the universe, since dark energy starts driving the expansion of the universe when matter perturbations become sufficiently dense. Here we study a possible realization of this general idea by coupling dark energy to dark matter via the linear growth function of matter perturbations. The numerical results show that it is indeed possible to obtain a viable cosmology with the expected series of radiation, matter and dark-energy dominated eras. Moreover, the current density of dark energy is given by the value of the coupling parameters rather than by very special initial conditions for the scalar field. In other words, this ...

  9. Double-Disk Dark Matter

    E-Print Network [OSTI]

    Fan, JiJi; Randall, Lisa; Reece, Matthew

    2013-01-01

    Based on observational tests and constraints on halo structure, dark matter is generally taken to be cold and essentially collisionless. On the other hand, given the large number of particles and forces in the visible world, a more complex dark sector could be a reasonable or even likely possibility. This hypothesis leads to testable consequences, perhaps portending the discovery of a rich hidden world neighboring our own. We consider a scenario that readily satisfies current bounds that we call Partially Interacting Dark Matter (PIDM). This scenario contains self-interacting dark matter, but it is not the dominant component. Even if PIDM contains only a fraction of the net dark matter density, comparable to the baryonic fraction, the subdominant component's interactions can lead to interesting and potentially observable consequences. Our primary focus will be the special case of Double-Disk Dark Matter (DDDM), in which self-interactions allow the dark matter to lose enough energy to lead to dynamics similar ...

  10. Dark matter on the lattice

    E-Print Network [OSTI]

    Randy Lewis

    2014-11-26

    Several collaborations have recently performed lattice calculations aimed specifically at dark matter, including work with SU(2), SU(3), SU(4) and SO(4) gauge theories to represent the dark sector. Highlights of these studies are presented here, after a reminder of how lattice calculations in QCD itself are helping with the hunt for dark matter.

  11. A quantized frequency reference in the short-ranged gravity potential and its application for dark matter and dark energy searches

    E-Print Network [OSTI]

    T. Jenke; G. Cronenberg; P. Geltenbort; A. N. Ivanov; T. Lauer; T. Lins; U. Schmidt; H. Saul; H. Abele

    2012-08-19

    The evidence for the observation of the Higgs spin-0-boson as a manifestation of a scalar field provides the missing corner stone for the standard model of particles (SM). However, the SM fails to explain the non-visible but gravitationally active part of the universe. Its nature is unknown but the confirmation of a scalar Higgs is giving a boost to scalar-field-theories. So far gravity experiments and observations performed at different distances find no deviation from Newton's gravity law. Therefore dark energy must possess a screening mechanism which suppresses the scalar-mediated fifth force. Our line of attack is a novel gravity experiment with neutrons based on a quantum interference technique. The spectroscopic measurement of quantum states on resonances with an external coupling makes this a powerful search for dark matter and dark energy contributions in the universe. Quantum states in the gravity potential are intimately related to other scalar field or spin-0-bosons if they exist. If the reason is that some undiscovered particle interact with a neutron, this results in a measurable energy shift of quantum states in the gravity potential, because for neutrons the screening effect is absent. We use Gravity Resonance Spectroscopy to measure the energy splitting at the highest level of precision, providing a constraint on any possible new interaction. We obtain a sensitivity of 10^-14 eV. We set an experimental limit on any fifth force, in particular on parameter \\beta<2x10^9 at n=3 for the scalar chameleon field, which is improved by a factor of 100 compared to our previous experiment and five orders of magnitude better than from precision tests of atomic spectra. The pseudoscalar axion coupling is constrained to gsgp/\\hbar c<3x10^-16 at 20\\mu m, which is an improvement by a factor of 30. These results indicate that gravity is understood at this improved level of precision.

  12. Self-Interacting Dark Matter

    E-Print Network [OSTI]

    Benjamin D. Wandelt; Romeel Dave; Glennys R. Farrar; Patrick C. McGuire; David N. Spergel; Paul J. Steinhardt

    2000-06-28

    Spergel and Steinhardt have recently proposed the concept of dark matter with strong self-interactions as a means to address numerous discrepancies between observations of dark matter halos on subgalactic scales and the predictions of the standard collisionless dark matter picture. We review the motivations for this scenario and discuss some recent, successful numerical tests. We also discuss the possibility that the dark matter interacts strongly with ordinary baryonic matter, as well as with itself. We present a new analysis of the experimental constraints and re-evaluate the allowed range of cross-section and mass.

  13. The Alpha Magnetic Spectrometer (AMS): search for antimatter and dark matter on the International Space Station

    E-Print Network [OSTI]

    R. Battiston

    1997-08-27

    The AMS is a state of the art detector for extraterrestrial study of antimatter, matter and missing matter. After a precursor flight on STS91 in May 1998, AMS will be installed on the International Space Station where it will operate for three years. In this paper the AMS experiment is described and is physics potential reviewed.

  14. Dark Matter Velocity Spectroscopy

    E-Print Network [OSTI]

    Eric G. Speckhard; Kenny C. Y. Ng; John F. Beacom; Ranjan Laha

    2015-07-31

    Dark matter decays or annihilations that produce line-like spectra may be smoking-gun signals. However, even such distinctive signatures can be mimicked by astrophysical or instrumental causes. We show that velocity spectroscopy-the measurement of energy shifts induced by relative motion of source and observer-can separate these three causes with minimal theoretical uncertainties. The principal obstacle has been energy resolution, but upcoming experiments will reach the required 0.1% level. As an example, we show that the imminent Astro-H mission can use Milky Way observations to separate possible causes of the 3.5-keV line. We discuss other applications.

  15. Dark matter axions

    SciTech Connect (OSTI)

    Sikivie, P. (California Univ., Santa Barbara, CA (United States). Inst. for Theoretical Physics Florida Univ., Gainesville, FL (United States). Dept. of Physics)

    1992-01-01

    The physics of axions is briefly reviewed theoretically, and various constraints on the axion mass are recounted. Then the two main contributions to the present cosmological axion energy density, that due to the realignment of the vacuum during the QCD phase transition and that from axions radiated by cosmic axion strings, are discussed. Next, two detection schemes for axions that are sensitive to different mass ranges, an electromagnetic cavity permeated by a strong magnetic field and a system of superconducting wires embedded in a material transparent to microwave radiation, are described. Finally, the phase space structure of cold dark matter galactic halos is considered. (RWR)

  16. Dark matter axions

    SciTech Connect (OSTI)

    Sikivie, P. [California Univ., Santa Barbara, CA (United States). Inst. for Theoretical Physics]|[Florida Univ., Gainesville, FL (United States). Dept. of Physics

    1992-09-01

    The physics of axions is briefly reviewed theoretically, and various constraints on the axion mass are recounted. Then the two main contributions to the present cosmological axion energy density, that due to the realignment of the vacuum during the QCD phase transition and that from axions radiated by cosmic axion strings, are discussed. Next, two detection schemes for axions that are sensitive to different mass ranges, an electromagnetic cavity permeated by a strong magnetic field and a system of superconducting wires embedded in a material transparent to microwave radiation, are described. Finally, the phase space structure of cold dark matter galactic halos is considered. (RWR)

  17. Quantum vacuum and dark matter

    E-Print Network [OSTI]

    Dragan Slavkov Hajdukovic

    2011-11-21

    Recently, the gravitational polarization of the quantum vacuum was proposed as alternative to the dark matter paradigm. In the present paper we consider four benchmark measurements: the universality of the central surface density of galaxy dark matter haloes, the cored dark matter haloes in dwarf spheroidal galaxies, the non-existence of dark disks in spiral galaxies and distribution of dark matter after collision of clusters of galaxies (the Bullet cluster is a famous example). Only some of these phenomena (but not all of them) can (in principle) be explained by the dark matter and the theories of modified gravity. However, we argue that the framework of the gravitational polarization of the quantum vacuum allows the understanding of the totality of these phenomena.

  18. Interacting Dark Matter and Dark Energy

    E-Print Network [OSTI]

    Glennys R. Farrar; P. J. E. Peebles

    2003-09-23

    We discuss models for the cosmological dark sector in which the energy density of a scalar field approximates Einstein's cosmological constant and the scalar field value determines the dark matter particle mass by a Yukawa coupling. A model with one dark matter family can be adjusted so the observational constraints on the cosmological parameters are close to but different from what is predicted by the Lambda CDM model. This may be a useful aid to judging how tightly the cosmological parameters are constrained by the new generation of cosmological tests that depend on the theory of structure formation. In a model with two families of dark matter particles the scalar field may be locked to near zero mass for one family. This can suppress the long-range scalar force in the dark sector and eliminate evolution of the effective cosmological constant and the mass of the nonrelativistic dark matter particles, making the model close to Lambda CDM, until the particle number density becomes low enough to allow the scalar field to evolve. This is a useful example of the possibility for complexity in the dark sector.

  19. Dark Matter Search Results from the PICO-60 CF$_3$I Bubble Chamber (Journal

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing BacteriaConnect Collidertransfer (Journal Article)Journal Article: Dark

  20. Dark Matter Search Results from the PICO-60 CF$_3$I Bubble Chamber (Journal

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing BacteriaConnect Collidertransfer (Journal Article)Journal Article: DarkArticle) |

  1. Probing the Dark Sector with Dark Matter Bound States

    E-Print Network [OSTI]

    Haipeng An; Bertrand Echenard; Maxim Pospelov; Yue Zhang

    2015-10-16

    A model of dark sector where $O({\\rm few~GeV})$ mass dark matter particles $\\chi$ are supplied by a lighter dark force mediator $V$, $m_V \\ll m_\\chi$, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic haloes. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of $\\chi$, such as $0^{-+}$ and $1^{--}$ states, $\\eta_D$ and $ \\Upsilon_D$, is an important search channel. We show that $e^+e^-\\to \\eta_D +V$ or $\\Upsilon_D +\\gamma$ production at $B$-factories for $\\alpha_D > 0.1$ is sufficiently strong to result in multiple pairs of charged leptons and pions via $\\eta_D\\to 2V \\to 2(l^+l^-)$ and $\\Upsilon_D\\to 3V \\to 3(l^+l^-)$ $(l=e,\\mu,\\pi)$. The absence of such final states in the existing searches performed at BaBar and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, $e^+e^-\\to \\chi\\bar\\chi+nV$, resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter.

  2. Unified Description of Dark Energy and Dark Matter

    E-Print Network [OSTI]

    Walter Petry

    2008-11-09

    Dark energy in the universe is assumed to be vacuum energy. The energy-momentum of vacuum is described by a scale-dependent cosmological constant. The equations of motion imply for the density of matter (dust) the sum of the usual matter density (luminous matter) and an additional matter density (dark matter) similar to the dark energy. The scale-dependent cosmological constant is given up to an exponent which is approximated by the experimentally decided density parameters of dark matter and dark energy. This yields that dark matter is one third of dark energy for all times implying an explanation of the coincidence of dark matter and dark energy. In the final state, the universe becomes dark, consisting of dark matter and dark energy.

  3. Search of Dark Matter Annihilation in the Galactic Centre using the ANTARES Neutrino Telescope

    E-Print Network [OSTI]

    Adrián-Martínez, S; André, M; Anton, G; Ardid, M; Aubert, J -J; Baret, B; Barrios-Martí, J; Basa, S; Bertin, V; Biagi, S; Bogazzi, C; Bormuth, R; Bou-Cabo, M; Bouwhuis, M C; Bruijn, R; Brunner, J; Busto, J; Capone, A; Caramete, L; Carr, J; Chiarusi, T; Circella, M; Coniglione, R; Costantini, H; Coyle, P; Creusot, A; Dekeyser, I; Deschamps, A; DeBonis, G; Distefano, C; Donzaud, C; Dornic, D; Drouhin, D; Dumas, A; Eberl, T; Elsässer, D; Enzenhöfer, A; Fehn, K; Felis, I; Fermani, P; Folger, F; Fusco, L A; Galatà, S; Gay, P; Geißelsöder, S; Geyer, K; Giordano, V; Gleixner, A; Gracia-Ruiz, R; Graf, K; vanHaren, H; Heijboer, A J; Hello, Y; Hernández-Rey, J J; Herrero, A; Hößl, J; Hofestädt, J; Hugon, C; WJames, C; deJong, M; Kadler, M; Kalekin, O; Katz, U; Kießling, D; Kooijman, P; Kouchner, A; Kreykenbohm, I; Kulikovskiy, V; Lahmann, R; Lambard, G; Lattuada, D; Lefèvre, D; Leonora, E; Loucatos, S; Marcelin, M; Margiotta, A; Martínez-Mora, J A; Martini, S; Mathieu, A; Michael, T; Migliozzi, P; Moussa, A; Mueller, C; Neff, M; Nezri, E; P?v?la?, G E; Pellegrino, C; Perrina, C; Piattelli, P; Popa, V; Pradier, T; Racca, C; Riccobene, G; Richter, R; Roensch, K; Rostovtsev, A; Saldaña, M; Samtleben, D F E; Sanguineti, M; Sapienza, P; Schmid, J; Schnabel, J; Schulte, S; Schüssler, F; Seitz, T; Sieger, C; Spurio, M; Steijger, J J M; Stolarczyk, Th; Sánchez-Losa, A; Taiuti, M; Tamburini, C; Trovato, A; Tselengidou, M; Tönnis, C; Vallage, B; Vallée, C; VanElewyck, V; Visser, E; Vivolo, D; Wagner, S; Wilms, J; Zornoza, J D; Zúñiga, J

    2015-01-01

    A search for high-energy neutrinos coming from the direction of the Galactic Centre is performed using the data recorded by the ANTARES neutrino telescope from 2007 to 2012. The event selection criteria are chosen to maximise the sensitivity to possible signals produced by the self-annihilation of weakly interacting massive particles accumulated around the centre of the Milky Way with respect to the atmospheric background. After data unblinding, the number of neutrinos observed in the line of sight of the Galactic Centre is found to be compatible with background expectations. The 90% C.L. upper limits in terms of the neutrino+anti-neutrino flux, $\\rm \\Phi_{\

  4. Solving the Dark Matter Problem

    ScienceCinema (OSTI)

    Baltz, Ted

    2009-09-01

    Cosmological observations have firmly established that the majority of matter in the universe is of an unknown type, called 'dark matter'. A compelling hypothesis is that the dark matter consists of weakly interacting massive particles (WIMPs) in the mass range around 100 GeV. If the WIMP hypothesis is correct, such particles could be created and studied at accelerators. Furthermore they could be directly detected as the primary component of our galaxy. Solving the dark matter problem requires that the connection be made between the two. We describe some theoretical and experimental avenues that might lead to this connection.

  5. Dark matter burners

    E-Print Network [OSTI]

    Moskalenko, I V; Moskalenko, Igor V.; Wai, Lawrence L.

    2007-01-01

    We show that a star orbiting close enough to an adiabatically grown supermassive black hole (SMBH) can capture weakly interacting massive particles (WIMPs) at an extremely high rate. The stellar luminosity due to annihilation of captured WIMPs in the stellar core may be comparable to or even exceed the luminosity of the star due to thermonuclear burning. The model thus predicts the existence of unusual stars, essentially WIMP burners, in the vicinity of a SMBH. We find that the most efficient WIMP burners are stars with degenerate electron cores, e.g. white dwarfs (WDs); such WDs may have a very high surface temperature. If found, such stars would provide evidence for the existence of particle dark matter and can possibly be used to establish its density profile. On the other hand, the lack of such unusual stars may provide constraints on the WIMP density near the SMBH, as well as the WIMP-nucleus scattering and pair annihilation cross-sections.

  6. Dark matter burners

    E-Print Network [OSTI]

    Igor V. Moskalenko; Lawrence L. Wai

    2007-02-24

    We show that a star orbiting close enough to an adiabatically grown supermassive black hole (SMBH) can capture weakly interacting massive particles (WIMPs) at an extremely high rate. The stellar luminosity due to annihilation of captured WIMPs in the stellar core may be comparable to or even exceed the luminosity of the star due to thermonuclear burning. The model thus predicts the existence of unusual stars, essentially WIMP burners, in the vicinity of a SMBH. We find that the most efficient WIMP burners are stars with degenerate electron cores, e.g. white dwarfs (WDs); such WDs may have a very high surface temperature. If found, such stars would provide evidence for the existence of particle dark matter and can possibly be used to establish its density profile. On the other hand, the lack of such unusual stars may provide constraints on the WIMP density near the SMBH, as well as the WIMP-nucleus scattering and pair annihilation cross-sections.

  7. Search for the Production of Dark Matter in Association with Top-Quark Pairs in the Single-Lepton Final State in Proton-Proton Collisions at $\\sqrt{s}$ = 8 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.

    2015-06-17

    A search is presented for particle dark matter produced in association with a pair of top quarks in pp collisions at a centre-of-mass energy of s?=8 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 19.7 fb?1. This search requires the presence of one lepton, multiple jets, and large missing transverse energy. No excess of events is found above the SM expectation, and upper limits are derived on the production cross section. Interpreting the findings in the context of a scalar contact interaction between fermionic dark matter particles and topmore »quarks, lower limits on the interaction scale are set. These limits are also interpreted in terms of the dark matter-nucleon scattering cross sections for the spin-independent scalar operator and they complement direct searches for dark matter particles in the low mass region.« less

  8. Alternatives to Dark Matter and Dark Energy

    E-Print Network [OSTI]

    Philip D. Mannheim

    2005-08-01

    We review the underpinnings of the standard Newton-Einstein theory of gravity, and identify where it could possibly go wrong. In particular, we discuss the logical independence from each other of the general covariance principle, the equivalence principle and the Einstein equations, and discuss how to constrain the matter energy-momentum tensor which serves as the source of gravity. We identify the a priori assumption of the validity of standard gravity on all distance scales as the root cause of the dark matter and dark energy problems, and discuss how the freedom currently present in gravitational theory can enable us to construct candidate alternatives to the standard theory in which the dark matter and dark energy problems could then be resolved. We identify three generic aspects of these alternate approaches: that it is a universal acceleration scale which determines when a luminous Newtonian expectation is to fail to fit data, that there is a global cosmological effect on local galactic motions which can replace galactic dark matter, and that to solve the cosmological constant problem it is not necessary to quench the cosmological constant itself, but only the amount by which it gravitates.

  9. Search for muon signal from dark matter annihilations in the Sun with the Baksan Underground Scintillator Telescope for 24.12 years

    SciTech Connect (OSTI)

    Boliev, M.M.; Demidov, S.V.; Mikheyev, S.P.; Suvorova, O.V. E-mail: demidov@ms2.inr.ac.ru E-mail: suvorova@cpc.inr.ac.ru

    2013-09-01

    We present a new dataset analysis of the neutrino experiment at the Baksan Underground Scintillator Telescope with muon energy threshold about 1 GeV for the longest exposure time toward the Sun. In search for a signal from self-annihilations of dark matter particles in the center of the Sun we use an updated sample of upward through-going muons for 24.12 years of live time. No observable excess has been found in measured muons relative to expected background from neutrinos of atmospheric origin. We present an improved data analysis procedure and describe it in detail. We set the 90% C.L. new upper limits on expected neutrino and muon fluxes from dark matter annihilations in the Sun, on the corresponding annihilation rates and cross sections of their elastic scattering off proton.

  10. Dark matter burners

    E-Print Network [OSTI]

    Moskalenko, I V

    2006-01-01

    We show that a star orbiting close enough to an adiabatically grown supermassive black hole can capture a large number of weakly interacting massive particles (WIMPs) during its lifetime. WIMP annihilation energy release in low- to medium-mass stars is comparable with or even exceeds the luminosity of such stars due to thermonuclear burning. The excessive energy release in the stellar core may result in an evolution scenario different from what is expected for a regular star. The model thus predicts the existence of unusual stars within the central parsec of galactic nuclei. If found, such stars would provide evidence for the existence of particle dark matter. The excess luminosity of such stars attributed to WIMP "burning" can be used to infer the local WIMP matter density. A white dwarf with a highly eccentric orbit around the central black hole may exhibit variations in brightness correlated with the orbital phase. On the other hand, white dwarfs shown to lack such orbital brightness variations can be used...

  11. Exploring nu signals in dark matter detectors

    E-Print Network [OSTI]

    Roni Harnik; Joachim Kopp; Pedro A. N. Machado

    2015-08-03

    We investigate standard and non-standard solar neutrino signals in direct dark matter detection experiments. It is well known that even without new physics, scattering of solar neutrinos on nuclei or electrons is an irreducible background for direct dark matter searches, once these experiments each the ton scale. Here, we entertain the possibility that neutrino interactions are enhanced by new physics, such as new light force carriers (for instance a "dark photon") or neutrino magnetic moments. We consider models with only the three standard neutrino flavors, as well as scenarios with extra sterile neutrinos. We find that low-energy neutrino--electron and neutrino--nucleus scattering rates can be enhanced by several orders of magnitude, potentially enough to explain the event excesses observed in CoGeNT and CRESST. We also investigate temporal modulation in these neutrino signals, which can arise from geometric effects, oscillation physics, non-standard neutrino energy loss, and direction-dependent detection efficiencies. We emphasize that, in addition to providing potential explanations for existing signals, models featuring new physics in the neutrino sector can also be very relevant to future dark matter searches, where, on the one hand, they can be probed and constrained, but on the other hand, their signatures could also be confused with dark matter signals.

  12. Higgs Portal Vector Dark Matter : Revisited

    E-Print Network [OSTI]

    Seungwon Baek; P. Ko; Wan-Il Park; Eibun Senaha

    2013-04-15

    We revisit the Higgs portal vector dark matter model including a hidden sector Higgs field that generates the mass of the vector dark matter. The model becomes renormalizable and has two scalar bosons, the mixtures of the standard model (SM) Higgs and the hidden sector Higgs bosons. The strong bound from direct detection such as XENON100 is evaded due to the cancellation mechanism between the contributions from two scalar bosons. As a result, the model becomes still viable in large range of dark matter mass, contrary to some claims in the literature. The Higgs properties are also affected, the signal strengths for the Higgs boson search being universally suppressed relative to the SM value, which could be tested at the LHC in the future.

  13. A search for particle dark matter using cryogenic germanium and silicon detectors in the one- and two- tower runs of CDMS-II at Soudan

    SciTech Connect (OSTI)

    Ogburn, Reuben Walter, IV; /Stanford U., Phys. Dept.

    2008-04-01

    Images of the Bullet Cluster of galaxies in visible light, X-rays, and through gravitational lensing confirm that most of the matter in the universe is not composed of any known form of matter. The combined evidence from the dynamics of galaxies and clusters of galaxies, the cosmic microwave background, big bang nucleosynthesis, and other observations indicates that 80% of the universe's matter is dark, nearly collisionless, and cold. The identify of the dar, matter remains unknown, but weakly interacting massive particles (WIMPs) are a very good candidate. They are a natural part of many supersymmetric extensions to the standard model, and could be produced as a nonrelativistic, thermal relic in the early universe with about the right density to account for the missing mass. The dark matter of a galaxy should exist as a spherical or ellipsoidal cloud, called a 'halo' because it extends well past the edge of the visible galaxy. The Cryogenic Dark Matter Search (CDMS) seeks to directly detect interactions between WIMPs in the Milky Way's galactic dark matter halo using crystals of germanium and silicon. Our Z-sensitive ionization and phonon ('ZIP') detectors simultaneously measure both phonons and ionization produced by particle interactions. In order to find very rare, low-energy WIMP interactions, they must identify and reject background events caused by environmental radioactivity, radioactive contaminants on the detector,s and cosmic rays. In particular, sophisticated analysis of the timing of phonon signals is needed to eliminate signals caused by beta decays at the detector surfaces. This thesis presents the firs two dark matter data sets from the deep underground experimental site at the Soudan Underground Laboratory in Minnesota. These are known as 'Run 118', with six detectors (1 kg Ge, 65.2 live days before cuts) and 'Run 119', with twelve detectors (1.5 kg Ge, 74.5 live days before cuts). They have analyzed all data from the two runs together in a single, combined analysis, with sensitivity to lower-energy interactions, careful control of data quality and stability, and further development of techniques for reconstructing event location and rejecting near-surface interactions from beta decays. They also present a revision to the previously published Run 119 analysis, a demonstration of the feasibility of a low-threshold (1 or 2 keV) analysis of Soudan data, and a review of the literature on charge generation and quenching relevant to the ionization signal.

  14. Double-Disk Dark Matter

    E-Print Network [OSTI]

    JiJi Fan; Andrey Katz; Lisa Randall; Matthew Reece

    2013-07-31

    Based on observational constraints on large scale structure and halo structure, dark matter is generally taken to be cold and essentially collisionless. On the other hand, given the large number of particles and forces in the visible world, a more complex dark sector could be a reasonable or even likely possibility. This hypothesis leads to testable consequences, perhaps portending the discovery of a rich hidden world neighboring our own. We consider a scenario that readily satisfies current bounds that we call Partially Interacting Dark Matter (PIDM). This scenario contains self-interacting dark matter, but it is not the dominant component. Even if PIDM contains only a fraction of the net dark matter density, comparable to the baryonic fraction, the subdominant component's interactions can lead to interesting and potentially observable consequences. Our primary focus will be the special case of Double-Disk Dark Matter (DDDM), in which self-interactions allow the dark matter to lose enough energy to lead to dynamics similar to those in the baryonic sector. We explore a simple model in which DDDM can cool efficiently and form a disk within galaxies, and we evaluate some of the possible observational signatures. The most prominent signal of such a scenario could be an enhanced indirect detection signature with a distinctive spatial distribution. Even though subdominant, the enhanced density at the center of the galaxy and possibly throughout the plane of the galaxy can lead to large boost factors, and could even explain a signature as large as the 130 GeV Fermi line. Such scenarios also predict additional dark radiation degrees of freedom that could soon be detectable and would influence the interpretation of future data, such as that from Planck and from the Gaia satellite. We consider this to be the first step toward exploring a rich array of new possibilities for dark matter dynamics.

  15. Search for a dark matter candidate produced in association with a single top quark in $p\\bar{p}$ collisions at $\\sqrt{s} = 1.96$ TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Anza, F.; Apollinari, G.; Appel, J.A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2012-02-01

    We report a new search for dark matter in a data sample of an integrated luminosity of 7.7 fb{sup -1} of Tevatron p{bar p} collisions at {radical}s = 1.96 TeV, collected by the CDF II detector. We search for production of a dark matter candidate, D, in association with a single top quark. We consider the hadronic decay mode of the top quark exclusively, yielding a final state of three jets with missing transverse energy. The data are consistent with the standard model; we thus set 95% confidence level upper limits on the cross section of the process p{bar p} {yields} t + D as a function of the mass of the dark-matter candidate. The limits are approximately 0.5 pb for a dark-matter particle with mass in the range of 0 - 150 GeV/c{sup 2}.

  16. Dark Matter Triggers of Supernovae

    E-Print Network [OSTI]

    Peter W. Graham; Surjeet Rajendran; Jaime Varela

    2015-05-17

    The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to $1.25 M_{\\odot}$ rules out primordial black holes with masses $\\sim 10^{19}$ gm - $10^{20}$ gm as a dominant constituent of the local dark matter density. Black holes with masses as large as $10^{24}$ gm will be excluded if recent observations by the NuStar collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range $10^{20}$ gm - $10^{22}$ gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism proposed in this paper can constrain a variety of other dark matter scenarios such as Q balls, annihilation/collision of large composite states of dark matter and models of dark matter where the accretion of dark matter leads to the formation of compact cores within the star. White dwarfs, with their astronomical lifetimes and sizes, can thus act as large space-time volume detectors enabling a unique probe of the properties of dark matter, especially of dark matter candidates that have low number density. This mechanism also raises the intriguing possibility that a class of supernova may be triggered through rare events induced by dark matter rather than the conventional mechanism of accreting white dwarfs that explode upon reaching the Chandrasekhar mass.

  17. Torsion Balance Search for Lorentz-invariance, Dark

    E-Print Network [OSTI]

    Torsion Balance Search for Lorentz-invariance, Dark Energy and Dark Matter Claire Cramer AAPT of unpolarized matter another particle's spin #12;Torsion balances Coulomb's torsion balance: A high precision-plated · magnetically shielded · 4 mirrors 2.6 cm #12;#12;The torsion balance apparatus feet pendulum magnetic shielding

  18. Alternatives to Dark Matter and Dark Energy

    E-Print Network [OSTI]

    Mannheim, P D

    2006-01-01

    We review the underpinnings of the standard Newton-Einstein theory of gravity, and identify where it could possibly go wrong. In particular, we discuss the logical independence from each other of the general covariance principle, the equivalence principle and the Einstein equations, and discuss how to constrain the matter energy-momentum tensor which serves as the source of gravity. We identify the a priori assumption of the validity of standard gravity on all distance scales as the root cause of the dark matter and dark energy problems, and discuss how the freedom currently present in gravitational theory can enable us to construct candidate alternatives to the standard theory in which the dark matter and dark energy problems could then be resolved. We identify three generic aspects of these alternate approaches: that it is a universal acceleration scale which determines when a luminous Newtonian expectation is to fail to fit data, that there is a global cosmological effect on local galactic motions which ca...

  19. Window in the dark matter exclusion limits

    SciTech Connect (OSTI)

    Zaharijas, Gabrijela; Farrar, Glennys R. [Center for Cosmology and Particle Physics, New York University, New York, New York 10003 (United States)

    2005-10-15

    We consider the cross section limits for light dark matter cadnidates (m=0.4 to 10 GeV). We calculate the interaction of dark matter in the crust above underground dark matter detectors and find that in the intermediate cross section range, the energy loss of dark matter is sufficient to fall below the energy threshold of current underground experiments. This implies the existence of a window in the dark matter exclusion limits in the micro-barn range.

  20. Weak Lensing: Dark Matter, Dark Energy

    SciTech Connect (OSTI)

    Jain, Bhuvnesh (University of Pennsylvania) [University of Pennsylvania

    2006-02-27

    The light rays from distant galaxies are deflected by massive structures along the line of sight, causing the galaxy images to be distorted. Measurements of these distortions, known as weak lensing, provide a way of measuring the distribution of dark matter as well as the spatial geometry of the universe. I will describe the ideas underlying this approach to cosmology. With planned large imaging surveys, weak lensing is a powerful probe of dark energy. I will discuss the observational challenges ahead and recent progress in developing multiple, complementary approaches to lensing measurements.

  1. Astronomical Evidence for Dark Matter

    E-Print Network [OSTI]

    Golwala, Sunil

    dark matter (assumed non-baryonic) #12;A word about constitutes an energy density from the Friedmann Equation: (Assuming no curvature) #12;Definitions C Critical Density X X/C = 1 => flat universe, what Rotation curve: Virial Theorem: #12;Spiral Galaxies Luminous Matter ~ follows: Asymptotes to constant value

  2. Asymmetric capture of Dirac dark matter by the Sun

    E-Print Network [OSTI]

    Mattias Blennow; Stefan Clementz

    2015-08-19

    Current problems with the solar model may be alleviated if a significant amount of dark matter from the galactic halo is captured in the Sun. We discuss the capture process in the case where the dark matter is a Dirac fermion and the background halo consists of equal amounts of dark matter and anti-dark matter. By considering the case where dark matter and anti-dark matter have different cross sections on solar nuclei as well as the case where the capture process is considered to be a Poisson process, we find that a significant asymmetry between the captured dark particles and anti-particles is possible even for an annihilation cross section in the range expected for thermal relic dark matter. Since the captured number of particles are competitive with asymmetric dark matter models in a large range of parameter space, one may expect solar physics to be altered by the capture of Dirac dark matter. It is thus possible that solutions to the solar composition problem may be searched for in these type of models.

  3. Dark Matter and Dark Energy: Summary and Future Directions

    E-Print Network [OSTI]

    John Ellis

    2003-04-10

    This paper reviews the progress reported at this Royal Society Discussion Meeting and advertizes some possible future directions in our drive to understand dark matter and dark energy. Additionally, a first attempt is made to place in context the exciting new results from the WMAP satellite, which were published shortly after this Meeting. In the first part of this review, pieces of observational evidence shown here that bear on the amounts of dark matter and dark energy are reviewed. Subsequently, particle candidates for dark matter are mentioned, and detection strategies are discussed. Finally, ideas are presented for calculating the amounts of dark matter and dark energy, and possibly relating them to laboratory data.

  4. The XENON100 Dark Matter Experiment

    SciTech Connect (OSTI)

    Tziaferi, E.

    2010-06-23

    The XENON100 experiment is searching for WIMPs, which are particles that may consist dark matter. It is located in the underground laboratory of Gran Sasso (LNGS) in Italy at a depth of {approx}3600 m.w.e.. The experiment description, its performance and the expected background based on Monte Carlo simulations and material screening along with the projected sensitivities of the experiment are presented. In addition, a brief description of the upgrade XENON100 detector is given.

  5. Bimetric gravity and dark matter

    E-Print Network [OSTI]

    Laura Bernard; Luc Blanchet; Lavinia Heisenberg

    2015-07-10

    We review some recent proposals for relativistic models of dark matter in the context of bimetric gravity. The aim is to solve the problems of cold dark matter (CDM) at galactic scales, and to reproduce the phenomenology of the modified Newtonian dynamics (MOND), while still being in agreement with the standard cosmological model $\\Lambda$-CDM at large scales. In this context a promising alternative is dipolar dark matter (DDM) in which two different species of dark matter particles are separately coupled to the two metrics of bigravity and are linked together by an internal vector field. The phenomenology of MOND then results from a mechanism of gravitational polarization. Probably the best formulation of the model is within the framework of recently developed massive bigravity theories. Then the gravitational sector of the model is safe by construction, but a ghostly degree of freedom in the decoupling limit is still present in the dark matter sector. Future work should analyse the cosmological solutions of the model and check the post-Newtonian parameters in the solar system.

  6. Dark Matter in 3D

    SciTech Connect (OSTI)

    Alves, Daniele S.M.; Hedri, Sonia El; Wacker, Jay G.

    2012-04-01

    We discuss the relevance of directional detection experiments in the post-discovery era and propose a method to extract the local dark matter phase space distribution from directional data. The first feature of this method is a parameterization of the dark matter distribution function in terms of integrals of motion, which can be analytically extended to infer properties of the global distribution if certain equilibrium conditions hold. The second feature of our method is a decomposition of the distribution function in moments of a model independent basis, with minimal reliance on the ansatz for its functional form. We illustrate our method using the Via Lactea II N-body simulation as well as an analytical model for the dark matter halo. We conclude that O(1000) events are necessary to measure deviations from the Standard Halo Model and constrain or measure the presence of anisotropies.

  7. A Search for dark matter in events with one jet and missing transverse energy in $p\\bar{p}$ collisions at $\\sqrt{s} = 1.96$ TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; /Dubna, JINR /Texas A-M

    2012-03-01

    We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp collisions at {radical}s = 1.96 TeV corresponding to an integrated luminosity of 6.7 fb{sup -1} recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c{sup 2}, and on spin-dependent interactions up to masses of 200 GeV/c{sup 2}.

  8. Discovering Inelastic Thermal-Relic Dark Matter at Colliders

    E-Print Network [OSTI]

    Izaguirre, Eder; Shuve, Brian

    2015-01-01

    Dark Matter particles with inelastic interactions are ubiquitous in extensions of the Standard Model, yet remain challenging to fully probe with existing strategies. We propose a series of powerful searches at hadron and lepton colliders that are sensitive to inelastic dark matter dynamics. In representative models, we find that the LHC and BaBar could offer strong sensitivity to the thermal-relic dark matter parameter space for dark matter masses between ~100 MeV-100 GeV and fractional mass-splittings above the percent level; future searches at Belle II with a dedicated monophoton trigger could also offer sensitivity to thermal-relic scenarios with masses below a few GeV. Thermal scenarios with either larger masses or splittings are largely ruled out; lower masses remain viable yet may be accessible with other search strategies.

  9. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A.B.; Nygren, D.

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at themore »136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.« less

  10. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    SciTech Connect (OSTI)

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A.B.; Nygren, D.

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at the 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.

  11. Two-portal Dark Matter

    E-Print Network [OSTI]

    Karim Ghorbani; Hossein Ghorbani

    2015-06-14

    We propose a renormalizable dark matter model in which a fermionic dark matter (DM) candidate communicates with the standard model particles through two distinct portals: Higgs and vector portals. The dark sector is charged under a $U(1)'$ gauge symmetry while the standard model has a leptophobic interaction with the dark vector boson. The leading contribution of DM-nucleon elastic scattering cross section begins at one-loop level. The model meets all the constraints imposed by direct detection experiments provided by LUX and XENON100, observed relic abundance according to WMAP and Planck, and the invisible Higgs decay width measured at the LHC. It turns out that the dark matter mass in the viable parameter space can take values from a few GeV up to 1 TeV. This is a new feature which is absent in the models with only one portal. In addition, we can find in the constrained regions of the parameter space a DM mass of $\\sim 34$ GeV annihilating into $b$ quark pair, which explains the Fermi-LAT gamma-ray excess.

  12. Singlet fermionic dark matter as a natural higgs portal model

    E-Print Network [OSTI]

    Yeong Gyun Kim; Kang Young Lee; Seodong Shin

    2008-09-17

    We propose a renormalizable model of a fermionic dark matter by introducing a gauge singlet Dirac fermion and a real singlet scalar. The bridges between the singlet sector and the standard model sector are only the singlet scalar interaction terms with the standard model Higgs field. The singlet fermion couples to the standard model particles through the mixing between the standard model Higgs and singlet scalar and is naturally a weakly interacting massive particle (WIMP). The measured relic abundance can be explained by the singlet fermionic dark matter as the WIMP within this model. Collider implication of the singlet fermionic dark matter is also discussed. Predicted is the elastic scattering cross section of the singlet fermion into target nuclei for a direct detection of the dark matter. Search of the direct detection of the dark matter provides severe constraints on the parameters of our model.

  13. Catalysis of Electroweak Baryogenesis via Fermionic Higgs Portal Dark Matter

    E-Print Network [OSTI]

    Wei Chao; Michael J. Ramsey-Musolf

    2015-02-27

    We investigate catalysis of electroweak baryogenesis by fermionic Higgs portal dark matter using a two Higgs doublet model augmented by vector-like fermions. The lightest neutral fermion mass eigenstate provides a viable dark matter candidate in the presence of a stabilizing symmetry Z_2 or gauged U(1)_D symmetry. Allowing for a non-vanishing CP-violating phase in the lowest-dimension Higgs portal dark matter interactions allows generation of the observed dark matter relic density while evading direct detection bounds. The same phase provides a source for electroweak baryogenesis. We show that it is possible to obtain the observed abundances of visible and dark matter while satisfying present bounds from electric dipole moment (EDM) searches and direct detection experiments. Improving the present electron (neutron) EDM sensitivity by one (two) orders of magnitude would provide a conclusive test of this scenario.

  14. Cosmological Radio Emission induced by WIMP Dark Matter

    E-Print Network [OSTI]

    N. Fornengo; R. Lineros; M. Regis; M. Taoso

    2012-03-05

    We present a detailed analysis of the radio synchrotron emission induced by WIMP dark matter annihilations and decays in extragalactic halos. We compute intensity, angular correlation, and source counts and discuss the impact on the expected signals of dark matter clustering, as well as of other astrophysical uncertainties as magnetic fields and spatial diffusion. Bounds on dark matter microscopic properties are then derived, and, depending on the specific set of assumptions, they are competitive with constraints from other indirect dark matter searches. At GHz frequencies, dark matter sources can become a significant fraction of the total number of sources with brightness below the microJansky level. We show that, at this level of fluxes (which are within the reach of the next-generation radio surveys), properties of the faint edge of differential source counts, as well as angular correlation data, can become an important probe for WIMPs.

  15. Inert-sterile neutrino: Cold or warm dark matter candidate

    SciTech Connect (OSTI)

    Gelmini, Graciela B.; Osoba, Efunwande [Department of Physics and Astronomy, UCLA, 475 Portola Plaza, Los Angeles, California 90095 (United States); Palomares-Ruiz, Sergio [Centro de Fisica Teorica de Particulas (CFTP), Instituto Superior Tecnico, P-1049-001, Lisboa (Portugal)

    2010-03-15

    In usual particle models, sterile neutrinos can account for the dark matter of the Universe only if they have masses in the keV range and are warm dark matter. Stringent cosmological and astrophysical bounds, in particular, imposed by x-ray observations, apply to them. We point out that in a particular variation of the inert doublet model, sterile neutrinos can account for the dark matter in the Universe and may be either cold or warm dark matter candidates, even for masses much above the keV range. These inert-sterile neutrinos, produced nonthermally in the early Universe, would be stable and have very small couplings to standard model particles, rendering very difficult their detection in either direct or indirect dark matter searches. Their existence could be revealed only by discovering other particles of the model in collider experiments.

  16. Neutrino Mass and Dark Matter

    E-Print Network [OSTI]

    David O. Caldwell

    1998-12-01

    Despite direct observations favoring a low mass density, a critical density universe with a neutrino component of dark matter provides the best existing model to explain the observed structure of the universe over more than three orders of magnitude in distance scale. In principle this hot dark matter could consist of one, two, or three species of active neutrinos. If all present indications for neutrino mass are correct, however, only the two-species (muon neutrino and tau neutrino) possibility works. This requires the existence of at least one light sterile neutrino to explain the solar electron neutrino deficit via nu(e)->nu(s), leaving nu(mu)->nu(tau) as the explanation for the anomalous nu(mu)/nu(e) ratio produced by atmospheric neutrinos, and having the LSND experiment demonstrating via anti-nu(mu)-> anti-nu(e) the mass difference between the light nu(e)-nu(s) pair and the heavier nu(mu)-nu(tau) pair required for dark matter. Other experiments do not conflict with the LSND results when all the experiments are analyzed in the same way, and when analyzed conservatively the LSND data is quite compatible with the mass difference needed for dark matter. Further support for this mass pattern is provided by the need for a sterile neutrino to rescue heavy-element nucleosynthesis in supernovae, and it could even aid the concordance in light element abundances from the early universe.

  17. The Dark Side: from Dark Energy & Dark Matter to Washington and Science Policy

    E-Print Network [OSTI]

    Collar, Juan I.

    The Dark Side: from Dark Energy & Dark Matter to Washington and Science Policy Presenter: Michael: The Map Room (www.maproom.com )1949 N. Hoyne #12;The Dark Side: from Dark Energy and Dark Matter to Washington and Science Policy Presenter: Michael S. Turner Time & Date: 7-9 PM Monday June 16, 2008 Location

  18. Dark Matter Theory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent Bonding Low-Cost2 DOE HQSiteo nspectroscopic resultsDark Energy:

  19. Search for the production of dark matter in association with top-quark pairs in the single-lepton final state in proton-proton collisions at ?s = 8 TeV

    E-Print Network [OSTI]

    Apyan, Aram

    A search is presented for particle dark matter produced in association with a pair of top quarks in pp collisions at a centre-of-mass energy of ?s = 8 TeV. The data were collected with the CMS detector at the LHC and ...

  20. Search for Dark Matter in Events with a Hadronically Decaying W or Z Boson and Missing Transverse Momentum in pp Collisions at ?s = 8 TeV with the ATLAS Detector

    E-Print Network [OSTI]

    Taylor, Frank E.

    A search is presented for dark matter pair production in association with a W or Z boson in pp collisions representing 20.3??fb[superscript ?1] of integrated luminosity at ?s = 8??TeV using data recorded with the ATLAS ...

  1. Superconducting Detectors for Super Light Dark Matter

    E-Print Network [OSTI]

    Yonit Hochberg; Yue Zhao; Kathryn M. Zurek

    2015-04-27

    We propose and study a new class of of superconducting detectors which are sensitive to O(meV) electron recoils from dark matter-electron scattering. Such devices could detect dark matter as light as the warm dark matter limit, mX > keV. We compute the rate of dark matter scattering off free electrons in a (superconducting) metal, including the relevant Pauli blocking factors. We demonstrate that classes of dark matter consistent with all astrophysical and terrestrial constraints could be detected by such detectors with a moderate size exposure.

  2. Superconducting Detectors for Super Light Dark Matter

    E-Print Network [OSTI]

    Hochberg, Yonit; Zurek, Kathryn M

    2015-01-01

    We propose and study a new class of of superconducting detectors which are sensitive to O(meV) electron recoils from dark matter-electron scattering. Such devices could detect dark matter as light as the warm dark matter limit, mX > keV. We compute the rate of dark matter scattering off free electrons in a (superconducting) metal, including the relevant Pauli blocking factors. We demonstrate that classes of dark matter consistent with all astrophysical and terrestrial constraints could be detected by such detectors with a moderate size exposure.

  3. Superconducting Detectors for Super Light Dark Matter

    E-Print Network [OSTI]

    Yonit Hochberg; Yue Zhao; Kathryn M. Zurek

    2015-11-11

    We propose and study a new class of superconducting detectors which are sensitive to O(meV) electron recoils from dark matter-electron scattering. Such devices could detect dark matter as light as the warm dark matter limit, mX > keV. We compute the rate of dark matter scattering off of free electrons in a (superconducting) metal, including the relevant Pauli blocking factors. We demonstrate that classes of dark matter consistent with terrestrial and cosmological/astrophysical constraints could be detected by such detectors with a moderate size exposure.

  4. Constraints on Majorana dark matter from a fourth lepton family

    SciTech Connect (OSTI)

    Hapola, Tuomas [Institute for Particle Physics Phenomenology, Durham University, South Road, Durham DH1 3LE (United Kingdom); Järvinen, Matti [Crete Center for Theoretical Physics, University of Crete, 71003 Heraklion (Greece); Kouvaris, Chris; Panci, Paolo; Virkajärvi, Jussi, E-mail: t.a.hapola@durham.ac.uk, E-mail: mjarvine@physics.uoc.gr, E-mail: kouvaris@cp3.dias.sdu.dk, E-mail: panci@cp3-origins.net, E-mail: virkajarvi@cp3-origins.net [CP "3-Origins and DIAS, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

    2014-02-01

    We study the possibility of dark matter in the form of heavy neutrinos from a fourth lepton family with helicity suppressed couplings such that dark matter is produced thermally via annihilations in the early Universe. We present all possible constraints for this scenario coming from LHC and collider physics, underground direct detectors, neutrino telescopes, and indirect astrophysical searches. Although we embed the WIMP candidate within a model of composite dynamics, the majority of our results are model independent and applicable to all models where heavy neutrinos with suppressed couplings account for the dark matter abundance.

  5. The Higgs boson, Supersymmetry and Dark Matter: Relations and Perspectives

    E-Print Network [OSTI]

    Alexandre Arbey; Marco Battaglia; Farvah Mahmoudi

    2015-04-20

    The discovery of a light Higgs boson at the LHC opens a broad program of studies and measurements to understand the role of this particle in connection with New Physics and Cosmology. Supersymmetry is the best motivated and most thoroughly formulated and investigated model of New Physics which predicts a light Higgs boson and can explain dark matter. This paper discusses how the study of the Higgs boson connects with the search for supersymmetry and for dark matter at the LHC and at a future $e^+e^-$ collider and with dedicated underground dark matter experiments.

  6. Maximum patch method for directional dark matter detection

    SciTech Connect (OSTI)

    Henderson, Shawn; Monroe, Jocelyn; Fisher, Peter [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Laboratory for Nuclear Science, MIT Kavli Institute for Astrophysics and Space Research, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2008-07-01

    Present and planned dark matter detection experiments search for WIMP-induced nuclear recoils in poorly known background conditions. In this environment, the maximum gap statistical method provides a way of setting more sensitive cross section upper limits by incorporating known signal information. We give a recipe for the numerical calculation of upper limits for planned directional dark matter detection experiments, that will measure both recoil energy and angle, based on the gaps between events in two-dimensional phase space.

  7. Gif Lectures on direct detection of Dark Matter

    E-Print Network [OSTI]

    Eric Armengaud

    2010-03-11

    These notes cover some of the topics associated with direct detection of dark matter at an introductory level. The general principles of dark matter search are summarized. The current status of some experiments is described, with an emphasis on bolometric and noble liquid techniques. Plots and illustrations associated to these notes may be found on transparencies presented during the lecture, on the web site of Gif school 2009.

  8. Heavy Dark Matter Through the Higgs Portal

    E-Print Network [OSTI]

    John March-Russell; Stephen M. West; Daniel Cumberbatch; Dan Hooper

    2008-06-17

    Motivated by Higgs Portal and Hidden Valley models, heavy particle dark matter that communicates with the supersymmetric Standard Model via pure Higgs sector interactions is considered. We show that a thermal relic abundance consistent with the measured density of dark matter is possible for masses up to $\\sim 30\\tev$. For dark matter masses above $\\sim 1\\tev$, non-perturbative Sommerfeld corrections to the annihilation rate are large, and have the potential to greatly affect indirect detection signals. For large dark matter masses, the Higgs-dark-matter-sector couplings are large and we show how such models may be given a UV completion within the context of so-called "Fat-Higgs" models. Higgs Portal dark matter provides an example of an attractive alternative to conventional MSSM neutralino dark matter that may evade discovery at the LHC, while still being within the reach of current and upcoming indirect detection experiments.

  9. Bose Einstein Condensation as Dark Energy and Dark Matter

    E-Print Network [OSTI]

    Masako Nishiyama; Masa-aki Morita; Masahiro Morikawa

    2004-03-24

    We study a cosmological model in which the boson dark matter gradually condensates into dark energy. Negative pressure associated with the condensate yields the accelerated expansion of the Universe and the rapid collapse of the smallest scale fluctuations into many black holes, which become the seeds of the first galaxies. The cycle of gradual sedimentation and rapid collapse of condensate repeats many times and self-regularizes the ratio of dark energy and dark matter to be order one.

  10. A Hidden Dark Matter Sector, Dark Radiation, and the CMB

    E-Print Network [OSTI]

    Chacko, Zackaria; Hong, Sungwoo; Okui, Takemichi

    2015-01-01

    We consider theories where dark matter is composed of a thermal relic of weak scale mass, whose couplings to the Standard Model (SM) are however too small to give rise to the observed abundance. Instead, the abundance is set by annihilation to light hidden sector states that carry no charges under the SM gauge interactions. In such a scenario the constraints from direct and indirect detection, and from collider searches for dark matter, can easily be satisfied. The masses of such light hidden states can be protected by symmetry if they are Nambu-Goldstone bosons, fermions, or gauge bosons. These states can then contribute to the cosmic energy density as dark radiation, leading to observable signals in the cosmic microwave background (CMB). Furthermore, depending on whether or not the light hidden sector states self-interact, the fraction of the total energy density that free-streams is either decreased or increased, leading to characteristic effects on both the scalar and tensor components of the CMB anisotro...

  11. Dark Matter Antibaryons from a Supersymmetric Hidden Sector

    E-Print Network [OSTI]

    Nikita Blinov; David E. Morrissey; Kris Sigurdson; Sean Tulin

    2012-12-03

    The cosmological origin of both dark and baryonic matter can be explained through a unified mechanism called hylogenesis where baryon and antibaryon number are divided between the visible sector and a GeV-scale hidden sector, while the Universe remains net baryon symmetric. The "missing" antibaryons, in the form of exotic hidden states, are the dark matter. We study model-building, cosmological, and phenomenological aspects of this scenario within the framework of supersymmetry, which naturally stabilizes the light hidden sector and electroweak mass scales. Inelastic dark matter scattering on visible matter destroys nucleons, and nucleon decay searches offer a novel avenue for the direct detection of the hidden antibaryonic dark matter sea.

  12. Dark Matter Antibaryons from a Supersymmetric Hidden Sector

    E-Print Network [OSTI]

    Blinov, Nikita; Sigurdson, Kris; Tulin, Sean

    2012-01-01

    The cosmological origin of both dark and baryonic matter can be explained through a unified mechanism called hylogenesis where baryon and antibaryon number are divided between the visible sector and a GeV-scale hidden sector, while the Universe remains net baryon symmetric. The "missing" antibaryons, in the form of exotic hidden states, are the dark matter. We study model-building, cosmological, and phenomenological aspects of this scenario within the framework of supersymmetry, which naturally stabilizes the light hidden sector and electroweak mass scales. Inelastic dark matter scattering on visible matter destroys nucleons, and nucleon decay searches offer a novel avenue for the direct detection of the hidden antibaryonic dark matter sea.

  13. The Cosmology of Composite Inelastic Dark Matter

    SciTech Connect (OSTI)

    Spier Moreira Alves, Daniele; Behbahani, Siavosh R.; /SLAC /Stanford U., ITP; Schuster, Philip; Wacker, Jay G.; /SLAC

    2011-08-19

    Composite dark matter is a natural setting for implementing inelastic dark matter - the O(100 keV) mass splitting arises from spin-spin interactions of constituent fermions. In models where the constituents are charged under an axial U(1) gauge symmetry that also couples to the Standard Model quarks, dark matter scatters inelastically off Standard Model nuclei and can explain the DAMA/LIBRA annual modulation signal. This article describes the early Universe cosmology of a minimal implementation of a composite inelastic dark matter model where the dark matter is a meson composed of a light and a heavy quark. The synthesis of the constituent quarks into dark hadrons results in several qualitatively different configurations of the resulting dark matter composition depending on the relative mass scales in the system.

  14. Composite dark matter from a model with composite Higgs boson

    E-Print Network [OSTI]

    Maxim Yu. Khlopov; Chris Kouvaris

    2008-10-10

    In a previous paper \\cite{Khlopov:2007ic}, we showed how the minimal walking technicolor model (WTC) can provide a composite dark matter candidate, by forming bound states between a -2 electrically charged techniparticle and a $^4He^{++}$. We studied the properties of these \\emph{techni-O-helium} $tOHe$ "atoms", which behave as warmer dark matter rather than cold. In this paper we extend our work on several different aspects. We study the possibility of a mixed scenario where both $tOHe$ and bound states between +2 and -2 electrically charged techniparticles coexist in the dark matter density. We argue that these newly proposed bound states solely made of techniparticles, although they behave as Weakly Interacting Massive Particles (WIMPs), due to their large elastic cross section with nuclei, can only account for a small percentage of the dark matter density. Therefore we conclude that within the minimal WTC, composite dark matter should be mostly composed of $tOHe$. Moreover in this paper, we put cosmological bounds in the masses of the techniparticles, if they compose the dark matter density. Finally we propose within this setup, a possible explanation of the discrepancy between the DAMA/NaI and DAMA/LIBRA findings and the negative results of CDMS and other direct dark matter searches that imply nuclear recoil measurement, which should accompany ionization.

  15. Stealth Dark Matter: Dark scalar baryons through the Higgs portal

    E-Print Network [OSTI]

    Thomas Appelquist; Richard C. Brower; Michael I. Buchoff; George T. Fleming; Xiao-Yong Jin; Joe Kiskis; Graham D. Kribs; Ethan T. Neil; James C. Osborn; Claudio Rebbi; Enrico Rinaldi; David Schaich; Chris Schroeder; Sergey Syritsyn; Pavlos Vranas; Evan Weinberg; Oliver Witzel

    2015-05-28

    We present a new model of "Stealth Dark Matter": a composite baryonic scalar of an $SU(N_D)$ strongly-coupled theory with even $N_D \\geq 4$. All mass scales are technically natural, and dark matter stability is automatic without imposing an additional discrete or global symmetry. Constituent fermions transform in vector-like representations of the electroweak group that permit both electroweak-breaking and electroweak-preserving mass terms. This gives a tunable coupling of stealth dark matter to the Higgs boson independent of the dark matter mass itself. We specialize to $SU(4)$, and investigate the constraints on the model from dark meson decay, electroweak precision measurements, basic collider limits, and spin-independent direct detection scattering through Higgs exchange. We exploit our earlier lattice simulations that determined the composite spectrum as well as the effective Higgs coupling of stealth dark matter in order to place bounds from direct detection, excluding constituent fermions with dominantly electroweak-breaking masses. A lower bound on the dark baryon mass $m_B \\gtrsim 300$ GeV is obtained from the indirect requirement that the lightest dark meson not be observable at LEP II. We briefly survey some intriguing properties of stealth dark matter that are worthy of future study, including: collider studies of dark meson production and decay; indirect detection signals from annihilation; relic abundance estimates for both symmetric and asymmetric mechanisms; and direct detection through electromagnetic polarizability, a detailed study of which will appear in a companion paper.

  16. How cold is cold dark matter?

    SciTech Connect (OSTI)

    Armendariz-Picon, Cristian; Neelakanta, Jayanth T., E-mail: armen@phy.syr.edu, E-mail: jtneelak@syr.edu [Department of Physics, Syracuse University, Syracuse, NY 13244-1130 (United States)

    2014-03-01

    If cold dark matter consists of particles, these must be non-interacting and non-relativistic by definition. In most cold dark matter models however, dark matter particles inherit a non-vanishing velocity dispersion from interactions in the early universe, a velocity that redshifts with cosmic expansion but certainly remains non-zero. In this article, we place model-independent constraints on the dark matter temperature to mass ratio, whose square root determines the dark matter velocity dispersion. We only assume that dark matter particles decoupled kinetically while non-relativistic, when galactic scales had not entered the horizon yet, and that their momentum distribution has been Maxwellian since that time. Under these assumptions, using cosmic microwave background and matter power spectrum observations, we place upper limits on the temperature to mass ratio of cold dark matter today (away from collapsed structures). These limits imply that the present cold dark matter velocity dispersion has to be smaller than 54 m/s. Cold dark matter has to be quite cold, indeed.

  17. Non-linear Higgs portal to Dark Matter

    E-Print Network [OSTI]

    I. Brivio; M. B. Gavela; L. Merlo; K. Mimasu; J. M. No; R. del Rey; V. Sanz

    2015-11-03

    The Higgs portal to scalar Dark Matter is considered in the context of non-linearly realised electroweak symmetry breaking. We determine the dominant interactions of gauge bosons and the physical Higgs particle $h$ to a scalar singlet dark matter candidate. Phenomenological consequences are also studied in detail, including the possibility of distinguishing this scenario from the standard Higgs portal in which the electroweak symmetry breaking is linearly realised. Two features of significant impact are: i) the connection between the electroweak scale $v$ and the Higgs particle departs from the $(v+h)$ functional dependence, as the Higgs field is not necessarily an exact electroweak doublet; ii) the presence of specific couplings that arise at different order in the non-linear and in the linear expansions. These facts deeply affect the dark matter relic abundance, as well as the expected signals in direct and indirect searches and collider phenomenology, where Dark Matter production rates are enhanced with respect to the standard portal.

  18. Higgs portal to Inflation and fermionic dark matter

    E-Print Network [OSTI]

    Aditya Aravind; Minglei Xiao; Jiang-Hao Yu

    2015-12-30

    We investigate an inflationary model involving a gauge singlet scalar and fermionic dark matter. The mixing between the singlet scalar and the Higgs boson provides a portal to dark matter. The inflaton could either be the Higgs boson or the singlet scalar, and slow roll inflation is realized via its non-minimal coupling to gravity. In this setup, the effective scalar potential is stabilized by the mixing between two scalars and coupling with dark matter. We study constraints from collider searches, relic density and direct detection, and find that dark matter mass should be around half the mass of either the Higgs boson or singlet scalar. Using the renormalization group equation improved scalar potential and putting all the constraints together, we show that the inflationary observables $n_s-r$ are consistent with current Planck data.

  19. Significant Gamma Lines from Inert Higgs Dark Matter

    E-Print Network [OSTI]

    Michael Gustafsson; Erik Lundstrom; Lars Bergstrom; Joakim Edsjo

    2007-10-05

    One way to unambiguously confirm the existence of particle dark matter and determine its mass would be to detect its annihilation into monochromatic gamma-rays in upcoming telescopes. One of the most minimal models for dark matter is the inert doublet model, obtained by adding another Higgs doublet with no direct coupling to fermions. For a mass between 40 and 80 GeV, the lightest of the new inert Higgs particles can give the correct cosmic abundance of cold dark matter in agreement with current observations. We show that for this scalar dark matter candidate, the annihilation signal of monochromatic \\gamma\\gamma and Z\\gamma final states would be exceptionally strong. The energy range and rates for these gamma-ray line signals make them ideal to search for with the soon upcoming GLAST satellite.

  20. Dynamics of dark energy with a coupling to dark matter

    SciTech Connect (OSTI)

    Boehmer, Christian G.; Caldera-Cabral, Gabriela; Maartens, Roy; Lazkoz, Ruth

    2008-07-15

    Dark energy and dark matter are the dominant sources in the evolution of the late universe. They are currently only indirectly detected via their gravitational effects, and there could be a coupling between them without violating observational constraints. We investigate the background dynamics when dark energy is modeled as exponential quintessence and is coupled to dark matter via simple models of energy exchange. We introduce a new form of dark sector coupling, which leads to a more complicated dynamical phase space and has a better physical motivation than previous mathematically similar couplings.

  1. Dark matter as a cancer hazard

    E-Print Network [OSTI]

    Chashchina, Olga

    2015-01-01

    We comment on the paper "Dark Matter collisions with the Human Body" by K.~Freese and C.~Savage (Phys.\\ Lett.\\ B {\\bf 717}, 25 (2012) [arXiv:1204.1339]) and describe a dark matter model for which the results of the previous paper do not apply. Within this mirror dark matter model, potentially hazardous objects, mirror micrometeorites, can exist potentially leading to diseases triggered by multiple mutations, such as cancer.

  2. Dark matter as a cancer hazard

    E-Print Network [OSTI]

    Olga Chashchina; Zurab Silagadze

    2015-09-17

    We comment on the paper "Dark Matter collisions with the Human Body" by K.~Freese and C.~Savage (Phys.\\ Lett.\\ B {\\bf 717}, 25 (2012) [arXiv:1204.1339]) and describe a dark matter model for which the results of the previous paper do not apply. Within this mirror dark matter model, potentially hazardous objects, mirror micrometeorites, can exist potentially leading to diseases triggered by multiple mutations, such as cancer.

  3. Galaxy Structure, Dark Matter, and Galaxy Formation

    E-Print Network [OSTI]

    David H. Weinberg

    1996-10-01

    The structure of galaxies, the nature of dark matter, and the physics of galaxy formation were the interlocking themes of DM 1996: Dark and Visible Matter in Galaxies and Cosmological Implications. In this conference summary report, I review recent observational and theoretical advances in these areas, then describe highlights of the meeting and discuss their implications. I include as an appendix the lyrics of The Dark Matter Rap: A Cosmological History for the MTV Generation.

  4. Dark matter annihilation or unresolved astrophysical sources...

    Office of Scientific and Technical Information (OSTI)

    should be a powerful tool for revealing the CGB origin, and potentially for the first detection of dark matter annihilation. Authors: Ando, Shin'ichiro ; Komatsu, Eiichiro ;...

  5. Dark Matter in the MSSM

    SciTech Connect (OSTI)

    Cotta, R.C.; Gainer, J.S.; Hewett, J.L.; Rizzo, T.G.; /SLAC

    2009-04-07

    We have recently examined a large number of points in the parameter space of the phenomenological MSSM, the 19-dimensional parameter space of the CP-conserving MSSM with Minimal Flavor Violation. We determined whether each of these points satisfied existing experimental and theoretical constraints. This analysis provides insight into general features of the MSSM without reference to a particular SUSY breaking scenario or any other assumptions at the GUT scale. This study opens up new possibilities for SUSY phenomenology both in colliders and in astrophysical experiments. Here we shall discuss the implications of this analysis relevant to the study of dark matter.

  6. BBN with light dark matter

    SciTech Connect (OSTI)

    Berezhiani, Zurab [Dipartimento di Fisica, Università dell'Aquila, Via Vetoio, 67100 Coppito, L'Aquila (Italy); Dolgov, Aleksander; Tkachev, Igor, E-mail: Zurab.Berezhiani@aquila.infn.it, E-mail: dolgov@fe.infn.it, E-mail: tkachev@ms2.inr.ac.ru [Laboratory of Cosmology and Elementary Particles, Novosibirsk State University, Pirogov street 2, 630090 Novosibirsk (Russian Federation)

    2013-02-01

    Effects of light millicharged dark matter particles on primordial nucleosynthesis are considered. It is shown that if the mass of such particles is much smaller than the electron mass, they lead to strong overproduction of Helium-4. An agreement with observations can be achieved by non-vanishing lepton asymmetry. Baryon-to-photon ratio at BBN and neutrino-to-photon ratio both at BBN and at recombination are noticeably different as compared to the standard cosmological model. The latter ratio and possible lepton asymmetry could be checked by Planck. For higher mass of new particles the effect is much less pronounced and may even have opposite sign.

  7. A Scenario of Heavy Baryonic Dark Matter

    E-Print Network [OSTI]

    Huo, Ran; Tsai, Yue-Lin Sming; Yanagida, Tsutomu T

    2015-01-01

    We consider a general class of models in which dark matter is a composite baryonic and antibaryonic particle of some hidden vector-like strong gauge theory. The model building provides simple answers to two basic questions: Annihilation between dark baryon and antibaryon saturates the unitarity bound, which in thermal freeze out predicts the scale of dark matter particle to be about 150 TeV. And the dark matter stability is a result of the accidental dark baryon number, which can still be violated by operators suppressed by large scales, leading to tiny decay rate. We show that annihilation between dark baryon and anti-baryon seems difficult to be detected in the galaxy center in the near future. On the other hand in the minimal model of $SU(3)$ hidden strong gauge group with a Planck scale suppression, the dark matter life time happens to be marginal to the current detection bound, and can explain the current AMS-02 antiproton results.

  8. Unified dark energy-dark matter model with inverse quintessence

    SciTech Connect (OSTI)

    Ansoldi, Stefano; Guendelman, Eduardo I. E-mail: guendel@bgu.ac.il

    2013-05-01

    We consider a model where both dark energy and dark matter originate from the coupling of a scalar field with a non-canonical kinetic term to, both, a metric measure and a non-metric measure. An interacting dark energy/dark matter scenario can be obtained by introducing an additional scalar that can produce non constant vacuum energy and associated variations in dark matter. The phenomenology is most interesting when the kinetic term of the additional scalar field is ghost-type, since in this case the dark energy vanishes in the early universe and then grows with time. This constitutes an ''inverse quintessence scenario'', where the universe starts from a zero vacuum energy density state, instead of approaching it in the future.

  9. Lepton-flavored dark matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kile, Jennifer; Kobach, Andrew; Soni, Amarjit

    2015-05-01

    In this work, we address two paradoxes. The first is that the measured dark-matter relic density can be satisfied with new physics at O(100 GeV–1 TeV), while the null results from direct-detection experiments place lower bounds of O(10 TeV) on a new-physics scale. The second puzzle is that the severe suppression of lepton-flavor-violating processes involving electrons, e.g. ? ? 3e, ? ? e??, etc., implies that generic new-physics contributions to lepton interactions cannot exist below O(10–100 TeV), whereas the 3.6? deviation of the muon g – 2 from the standard model can be explained by a new physics scale more »TeV). Here, we suggest that it may not be a coincidence that both the muon g – 2 and the relic density can be satisfied by a new-physics scale ?1 TeV. We consider the possibility of a gauged lepton-flavor interaction that couples at tree level only to ?- and ?-flavored leptons and the dark sector. Dark matter thus interacts appreciably only with particles of ? and ? flavor at tree level and has loop-suppressed couplings to quarks and electrons. Remarkably, if such a gauged flavor interaction exists at a scale O(100 GeV–1 TeV), it allows for a consistent phenomenological framework, compatible with the muon g – 2, the relic density, direct detection, indirect detection, charged-lepton decays, neutrino trident production, and results from hadron and e?e? colliders. We suggest experimental tests for these ideas at colliders and for low-energy observables. (author)« less

  10. Lepton-flavored dark matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kile, Jennifer; Kobach, Andrew; Soni, Amarjit

    2015-05-01

    In this work, we address two paradoxes. The first is that the measured dark-matter relic density can be satisfied with new physics at O(100 GeV–1 TeV), while the null results from direct-detection experiments place lower bounds of O(10 TeV) on a new-physics scale. The second puzzle is that the severe suppression of lepton-flavor-violating processes involving electrons, e.g. ? ? 3e, ? ? e??, etc., implies that generic new-physics contributions to lepton interactions cannot exist below O(10–100 TeV), whereas the 3.6? deviation of the muon g – 2 from the standard model can be explained by a new physics scale dark sector. Dark matter thus interacts appreciably only with particles of ? and ? flavor at tree level and has loop-suppressed couplings to quarks and electrons. Remarkably, if such a gauged flavor interaction exists at a scale O(100 GeV–1 TeV), it allows for a consistent phenomenological framework, compatible with the muon g – 2, the relic density, direct detection, indirect detection, charged-lepton decays, neutrino trident production, and results from hadron and e?e? colliders. We suggest experimental tests for these ideas at colliders and for low-energy observables. (author)

  11. Continuous flavor symmetries and the stability of asymmetric dark matter

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bishara, Fady; Zupan, Jure

    2015-01-19

    Generically, the asymmetric interactions in asymmetric dark matter (ADM) models could lead to decaying DM. We show that, for ADM that carries nonzero baryon number, the continuous flavor symmetries that generate the flavor structure in the quark sector also imply a looser lower bound on the mass scale of the asymmetric mediators between the dark and visible sectors. The mediators for B = 2 ADM that can produce a signal in the future indirect dark matter searches can thus also be searched for at the LHC. For two examples of the mediator models, with either the MFV or Froggatt-Nielsen flavormore »breaking pattern, we derive the FCNC constraints and discuss the search strategies at the LHC.« less

  12. Continuous flavor symmetries and the stability of asymmetric dark matter

    SciTech Connect (OSTI)

    Bishara, Fady [University of Cincinnati, Cincinnati, OH (United States); Fermi National Accelerator Laboratory, Batavia, IL (Unitd States); Zupan, Jure [Fermi National Accelerator Laboratory, Batavia, IL (Unitd States)

    2015-01-01

    Generically, the asymmetric interactions in asymmetric dark matter (ADM) models could lead to decaying DM. We show that, for ADM that carries nonzero baryon number, the continuous flavor symmetries that generate the flavor structure in the quark sector also imply a looser lower bound on the mass scale of the asymmetric mediators between the dark and visible sectors. The mediators for B = 2 ADM that can produce a signal in the future indirect dark matter searches can thus also be searched for at the LHC. For two examples of the mediator models, with either the MFV or Froggatt-Nielsen flavor breaking pattern, we derive the FCNC constraints and discuss the search strategies at the LHC.

  13. A Radio for Hidden-Photon Dark Matter Detection

    E-Print Network [OSTI]

    Saptarshi Chaudhuri; Peter W. Graham; Kent Irwin; Jeremy Mardon; Surjeet Rajendran; Yue Zhao

    2015-10-13

    We propose a resonant electromagnetic detector to search for hidden-photon dark matter over an extensive range of masses. Hidden-photon dark matter can be described as a weakly coupled "hidden electric field," oscillating at a frequency fixed by the mass, and able to penetrate any shielding. At low frequencies (compared to the inverse size of the shielding), we find that observable effect of the hidden photon inside any shielding is a real, oscillating magnetic field. We outline experimental setups designed to search for hidden-photon dark matter, using a tunable, resonant LC circuit designed to couple to this magnetic field. Our "straw man" setups take into consideration resonator design, readout architecture and noise estimates. At high frequencies,there is an upper limit to the useful size of a single resonator set by $1/\

  14. A Radio for Hidden-Photon Dark Matter Detection

    E-Print Network [OSTI]

    Saptarshi Chaudhuri; Peter W. Graham; Kent Irwin; Jeremy Mardon; Surjeet Rajendran; Yue Zhao

    2014-11-26

    We propose a resonant electromagnetic detector to search for hidden-photon dark matter over an extensive range of masses. Hidden-photon dark matter can be described as a weakly coupled "hidden electric field," oscillating at a frequency fixed by the mass, and able to penetrate any shielding. At low frequencies (compared to the inverse size of the shielding), we find that observable effect of the hidden photon inside any shielding is a real, oscillating magnetic field. We outline experimental setups designed to search for hidden-photon dark matter, using a tunable, resonant LC circuit designed to couple to this magnetic field. Our "straw man" setups take into consideration resonator design, readout architecture and noise estimates. At high frequencies,there is an upper limit to the useful size of a single resonator set by $1/\

  15. The Past and Future of Light Dark Matter Direct Detection

    E-Print Network [OSTI]

    Jonathan H. Davis

    2015-06-12

    We review the status and future of direct searches for light dark matter. We start by answering the question: `Whatever happened to the light dark matter anomalies?' i.e. the fate of the potential dark matter signals observed by the CoGeNT, CRESST-II, CDMS-Si and DAMA/LIBRA experiments. We discuss how the excess events in the first two of these experiments have been explained by previously underestimated backgrounds. For DAMA we summarise the progress and future of mundane explanations for the annual modulation reported in its event rate. Concerning the future of direct detection we focus on the irreducible background from solar neutrinos. We explain broadly how it will affect future searches and summarise efforts to mitigate its effects.

  16. A Hidden Dark Matter Sector, Dark Radiation, and the CMB

    E-Print Network [OSTI]

    Zackaria Chacko; Yanou Cui; Sungwoo Hong; Takemichi Okui

    2015-05-15

    We consider theories where dark matter is composed of a thermal relic of weak scale mass, whose couplings to the Standard Model (SM) are however too small to give rise to the observed abundance. Instead, the abundance is set by annihilation to light hidden sector states that carry no charges under the SM gauge interactions. In such a scenario the constraints from direct and indirect detection, and from collider searches for dark matter, can easily be satisfied. The masses of such light hidden states can be protected by symmetry if they are Nambu-Goldstone bosons, fermions, or gauge bosons. These states can then contribute to the cosmic energy density as dark radiation, leading to observable signals in the cosmic microwave background (CMB). Furthermore, depending on whether or not the light hidden sector states self-interact, the fraction of the total energy density that free-streams is either decreased or increased, leading to characteristic effects on both the scalar and tensor components of the CMB anisotropy that allows these two cases to be distinguished. The magnitude of these signals depends on the number of light degrees of freedom in the hidden sector, and on the temperature at which it kinetically decouples from the SM. We consider a simple model that realizes this scenario, based on a framework in which the SM and hidden sector are initially in thermal equilibrium through the Higgs portal, and show that the resulting signals are compatible with recent Planck results, while large enough to be detected in upcoming experiments such as CMBPol and CMB Stage-IV. Invisible decays of the Higgs into hidden sector states at colliders can offer a complementary probe of this model.

  17. Search for Dark Matter and Large Extra Dimensions in pp Collisions Yielding a Photon and Missing Transverse Energy

    E-Print Network [OSTI]

    Bauer, Gerry P.

    Results are presented from a search for new physics in the final state containing a photon (?) and missing transverse energy (E?T). The data correspond to an integrated luminosity of 5.0??fb-1 collected in pp collisions ...

  18. Search for dark matter, extra dimensions, and unparticles in monojet events in proton-proton collisions at $\\sqrt{s}$ = 8 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan

    2015-05-29

    Results are presented from a search for particle dark matter (DM), extra dimensions, and unparticles using events containing a jet and an imbalance in transverse momentum. The data were collected by the CMS detector in proton-proton collisions at the LHC and correspond to an integrated luminosity of 19.7 fb$^{-1}$ at a centre-of-mass energy of 8 TeV. The number of observed events is found to be consistent with the standard model prediction. Limits are placed on the DM-nucleon scattering cross section as a function of the DM particle mass for spin-dependent and spin-independent interactions. Limits are also placed on the scale parameter $M_\\mathrm{D}$ in the ADD model of large extra dimensions, and on the unparticle model parameter $\\Lambda_\\mathrm{U}$. The constraints on ADD models and unparticles are the most stringent limits in this channel and those on the DM-nucleon scattering cross section are an improvement over previous collider results.

  19. Search for dark matter, extra dimensions, and unparticles in monojet events in proton-proton collisions at $\\sqrt{s}$ = 8 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan [Yerevan Physics Institute (Armenia); et al.,

    2015-05-01

    Results are presented from a search for particle dark matter (DM), extra dimensions, and unparticles using events containing a jet and an imbalance in transverse momentum. The data were collected by the CMS detector in proton-proton collisions at the LHC and correspond to an integrated luminosity of 19.7 fb$^{-1}$ at a centre-of-mass energy of 8 TeV. The number of observed events is found to be consistent with the standard model prediction. Limits are placed on the DM-nucleon scattering cross section as a function of the DM particle mass for spin-dependent and spin-independent interactions. Limits are also placed on the scale parameter $M_\\mathrm{D}$ in the ADD model of large extra dimensions, and on the unparticle model parameter $\\Lambda_\\mathrm{U}$. The constraints on ADD models and unparticles are the most stringent limits in this channel and those on the DM-nucleon scattering cross section are an improvement over previous collider results.

  20. Search for dark matter, extra dimensions, and unparticles in monojet events in proton-proton collisions at $\\sqrt{s}$ = 8 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan

    2015-05-29

    Results are presented from a search for particle dark matter (DM), extra dimensions, and unparticles using events containing a jet and an imbalance in transverse momentum. The data were collected by the CMS detector in proton-proton collisions at the LHC and correspond to an integrated luminosity of 19.7 fb$^{-1}$ at a centre-of-mass energy of 8 TeV. The number of observed events is found to be consistent with the standard model prediction. Limits are placed on the DM-nucleon scattering cross section as a function of the DM particle mass for spin-dependent and spin-independent interactions. Limits are also placed on the scalemore »parameter $M_\\mathrm{D}$ in the ADD model of large extra dimensions, and on the unparticle model parameter $\\Lambda_\\mathrm{U}$. The constraints on ADD models and unparticles are the most stringent limits in this channel and those on the DM-nucleon scattering cross section are an improvement over previous collider results.« less

  1. Dimensionless constants, cosmology and other dark matters

    E-Print Network [OSTI]

    Max Tegmark; Anthony Aguirre; Martin J Rees; Frank Wilczek

    2006-01-11

    We identify 31 dimensionless physical constants required by particle physics and cosmology, and emphasize that both microphysical constraints and selection effects might help elucidate their origin. Axion cosmology provides an instructive example, in which these two kinds of arguments must both be taken into account, and work well together. If a Peccei-Quinn phase transition occurred before or during inflation, then the axion dark matter density will vary from place to place with a probability distribution. By calculating the net dark matter halo formation rate as a function of all four relevant cosmological parameters and assessing other constraints, we find that this probability distribution, computed at stable solar systems, is arguably peaked near the observed dark matter density. If cosmologically relevant WIMP dark matter is discovered, then one naturally expects comparable densities of WIMPs and axions, making it important to follow up with precision measurements to determine whether WIMPs account for all of the dark matter or merely part of it.

  2. SUSY Tools for Dark Matter and at the Colliders

    E-Print Network [OSTI]

    Fawzi Boudjema; Joakim Edsjo; Paolo Gondolo

    2010-03-24

    With present and upcoming SUSY searches both directly, indirectly and at accelerators, the need for accurate calculations is large. We will here go through some of the tools available both from a dark matter point of view and at accelerators. For natural reasons, we will focus on public tools, even though there are some rather sophisticated private tools as well.

  3. New Gamma-Ray Contributions to Supersymmetric Dark Matter Annihilation

    E-Print Network [OSTI]

    Torsten Bringmann; Lars Bergstrom; Joakim Edsjo

    2008-09-13

    We compute the electromagnetic radiative corrections to all leading annihilation processes which may occur in the Galactic dark matter halo, for dark matter in the framework of supersymmetric extensions of the Standard Model (MSSM and mSUGRA), and present the results of scans over the parameter space that is consistent with present observational bounds on the dark matter density of the Universe. Although these processes have previously been considered in some special cases by various authors, our new general analysis shows novel interesting results with large corrections that may be of importance, e.g., for searches at the soon to be launched GLAST gamma-ray space telescope. In particular, it is pointed out that regions of parameter space where there is a near degeneracy between the dark matter neutralino and the tau sleptons, radiative corrections may boost the gamma-ray yield by up to three or four orders of magnitude, even for neutralino masses considerably below the TeV scale, and will enhance the very characteristic signature of dark matter annihilations, namely a sharp step at the mass of the dark matter particle. Since this is a particularly interesting region for more constrained mSUGRA models of supersymmetry, we use an extensive scan over this parameter space to verify the significance of our findings. We also re-visit the direct annihilation of neutralinos into photons and point out that, for a considerable part of the parameter space, internal bremsstrahlung is more important for indirect dark matter searches than line signals.

  4. Phenomenology of Dirac Neutralino Dark Matter

    SciTech Connect (OSTI)

    Buckley, Matthew R.; Hooper, Dan; Kumar, Jason

    2013-09-01

    In supersymmetric models with an unbroken R-symmetry (rather than only R-parity), the neutralinos are Dirac fermions rather than Majorana. In this article, we discuss the phenomenology of neutralino dark matter in such models, including the calculation of the thermal relic abundance, and constraints and prospects for direct and indirect searches. Due to the large elastic scattering cross sections with nuclei predicted in R-symmetric models, we are forced to consider a neutralino that is predominantly bino, with very little higgsino mixing. We find a large region of parameter space in which bino-like Dirac neutralinos with masses between 10 and 380 GeV can annihilate through slepton exchange to provide a thermal relic abundance in agreement with the observed cosmological density, without relying on coannihilations or resonant annihilations. The signatures for the indirect detection of Dirac neutralinos are very different than predicted in the Majorana case, with annihilations proceeding dominately to $\\tau^+ \\tau^-$, $\\mu^+ \\mu^-$ and $e^+ e^-$ final states, without the standard chirality suppression. And unlike Majorana dark matter candidates, Dirac neutralinos experience spin-independent scattering with nuclei through vector couplings (via $Z$ and squark exchange), leading to potentially large rates at direct detection experiments. These and other characteristics make Dirac neutralinos potentially interesting within the context of recent direct and indirect detection anomalies. We also discuss the case in which the introduction of a small Majorana mass term breaks the $R$-symmetry, splitting the Dirac neutralino into a pair of nearly degenerate Majorana states.

  5. Constraints on Light Dark Matter from Single-Photon Decays of Heavy Quarkonium

    E-Print Network [OSTI]

    Fernandez, Nicolas; Stengel, Patrick

    2015-01-01

    We investigate constraints on the interactions of light dark matter with Standard Model quarks in a framework with effective contact operators mediating the decay of heavy flavor bound state quarkonium to dark matter and a photon. When considered in combination with decays to purely invisible final states, constraints from heavy quarkonium decays at high intensity electron-positron colliders can complement missing energy searches at high energy colliders and provide sensitivity to dark matter masses difficult to probe at direct and indirect detection experiments. We calculate the approximate limits on the branching fraction for $\\Upsilon (1 S)$ decays to dark matter and a photon. Given the approximate limits on the branching fractions for all dimension 6 or lower contact operators, we present the corresponding limits on the interaction strength for each operator and the inferred limits on dark matter-nucleon scattering. Complementary constraints on dark matter annihilation from gamma-ray searches from dwarf s...

  6. Search for Dark Matter in the sky in the Fermi era This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Morselli, Aldo

    annihilation of dark matter particles is strong but there are competing astrophysical sources, such as pulsars is providing the measurement of the high energy (7 GeV to 1 TeV) cosmic ray electrons and positrons spectrum mainly on astrophysical sources of cosmic ray electrons and positrons which include the standard primary

  7. A Search for Dark Higgs Bosons

    SciTech Connect (OSTI)

    Lees, J.P.

    2012-06-08

    Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb{sup -1} of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the Standard Model-dark sector mixing angle and the dark sector coupling constant.

  8. Dark Matter and Gauged Flavor Symmetries

    E-Print Network [OSTI]

    Bishara, Fady; Kamenik, Jernej F; Stamou, Emmanuel; Zupan, Jure

    2015-01-01

    We investigate the phenomenology of flavored dark matter (DM). DM stability is guaranteed by an accidental ${\\mathcal Z}_3$ symmetry, a subgroup of the standard model (SM) flavor group that is not broken by the SM Yukawa interactions. We consider an explicit realization where the quark part of the SM flavor group is fully gauged. If the dominant interactions between DM and visible sector are through flavor gauge bosons, as we show for Dirac fermion flavored DM, then the DM mass is bounded between roughly $0.5$ TeV and $5$ TeV if the DM multiplet mass is split only radiatively. In general, however, no such relation exists. We demonstrate this using scalar flavored DM where the main interaction with the SM is through the Higgs portal. For both cases we derive constraints from flavor, cosmology, direct and indirect DM detection, and collider searches.

  9. A stable Higgs portal with vector dark matter

    E-Print Network [OSTI]

    Mateusz Duch; Bohdan Grzadkowski; Moritz McGarrie

    2015-09-23

    We explore an extension of the Standard Model by an additional U (1) gauge group and a complex scalar Higgs portal. As the scalar is charged under this gauge factor this simple model supplies a vector dark matter candidate satisfying the observed relic abundance and limits from direct dark matter searches. An additional Higgs-like state, that may be heavier or lighter than the observed Higgs, is present and satisfies LEP and LHC bounds whilst allowing for absolute stability of the electroweak vacuum in a range of parameter space.

  10. Search for neutrinos from annihilation of captured low-mass dark matter particles in the Sun by Super-Kamiokande

    E-Print Network [OSTI]

    The Super-Kamiokande Collaboration; :; K. Choi; K. Abe; Y. Haga; Y. Hayato; K. Iyogi; J. Kameda; Y. Kishimoto; M. Miura; S. Moriyama; M. Nakahata; Y. Nakano; S. Nakayama; H. Sekiya; M. Shiozawa; Y. Suzuki; A. Takeda; T. Tomura; R. A. Wendell; T. Irvine; 2 T. Kajita; I. Kametani; 2 K. Kaneyuki; K. P. Lee; Y. Nishimura; 2 K. Okumura; T. McLachlan; 2 L. Labarga; E. Kearns; J. L. Raaf; 4 J. L. Stone; L. R. Sulak; 4 S. Berkman; 5 H. A. Tanaka; 5 S. Tobayama; M. Goldhaber; G. Carminati; W. R. Kropp; S. Mine; A. Renshaw; M. B. Smy; H. W. Sobel; K. S. Ganezer; J. Hill; N. Hong; J. Y. Kim; I. T. Lim; T. Akiri; A. Himmel; K. Scholberg; C. W. Walter; T. Wongjirad; T. Ishizuka; S. Tasaka; J. S. Jang; J. G. Learned; S. Matsuno; S. N. Smith; T. Hasegawa; T. Ishida; T. Ishii; T. Kobayashi; T. Nakadaira; K. Nakamura; Y. Oyama; K. Sakashita; T. Sekiguchi; T. Tsukamoto; A. T. Suzuki; Y. Takeuchi; C. Bronner; S. Hirota; K. Huang; K. Ieki; M. Ikeda; T. Kikawa; A. Minamino; T. Nakaya; K. Suzuki; S. Takahashi; Y. Fukuda; Y. Itow; G. Mitsuka; P. Mijakowski; J. Hignight; J. Imber; C. K. Jung; C. Yanagisawa; H. Ishino; A. Kibayashi; Y. Koshio; T. Mori; M. Sakuda; T. Yano; Y. Kuno; R. Tacik; S. B. Kim; H. Okazawa; Y. Choi; K. Nishijima; M. Koshiba; Y. Totsuka; M. Yokoyama; K. Martens; Ll. Marti; M. R. Vagins; J. F. Martin; P. de Perio; A. Konaka; M. J. Wilking; S. Chen; Y. Zhang; R. J. Wilkes

    2015-03-16

    Super-Kamiokande (SK) can search for weakly interacting massive particles (WIMPs) by detecting neutrinos produced from WIMP annihilations occurring inside the Sun. In this analysis, we include neutrino events with interaction vertices in the detector in addition to upward-going muons produced in the surrounding rock. Compared to the previous result, which used the upward-going muons only, the signal acceptances for light (few-GeV/$c^2$ $\\sim$ 200-GeV/$c^2$) WIMPs are significantly increased. We fit 3903 days of SK data to search for the contribution of neutrinos from WIMP annihilation in the Sun. We found no significant excess over expected atmospheric-neutrino background and the result is interpreted in terms of upper limits on WIMP-nucleon elastic scattering cross sections under different assumptions about the annihilation channel. We set the current best limits on the spin-dependent (SD) WIMP-proton cross section for WIMP masses below 200 GeV/$c^2$ (at 10 GeV/$c^2$, 1.49$\\times 10^{-39}$ cm$^2$ for $\\chi\\chi\\rightarrow b \\bar{b}$ and 1.31$\\times 10^{-40}$ cm$^2$ for $\\chi\\chi\\rightarrow\\tau^+\\tau^-$ annihilation channels), also ruling out some fraction of WIMP candidates with spin-independent (SI) coupling in the few-GeV/$c^2$ mass range.

  11. Asymmetric dark matter in braneworld cosmology

    SciTech Connect (OSTI)

    Meehan, Michael T.; Whittingham, Ian B., E-mail: Michael.Meehan@my.jcu.edu.au, E-mail: Ian.Whittingham@jcu.edu.au [School of Engineering and Physical Sciences, James Cook University, Townsville, 4811 Australia (Australia)

    2014-06-01

    We investigate the effect of a braneworld expansion era on the relic density of asymmetric dark matter. We find that the enhanced expansion rate in the early universe predicted by the Randall-Sundrum II (RSII) model leads to earlier particle freeze-out and an enhanced relic density. This effect has been observed previously by Okada and Seto (2004) for symmetric dark matter models and here we extend their results to the case of asymmetric dark matter. We also discuss the enhanced asymmetric annihilation rate in the braneworld scenario and its implications for indirect detection experiments.

  12. Hidden photons in connection to dark matter

    SciTech Connect (OSTI)

    Andreas, Sarah; Ringwald, Andreas [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Goodsell, Mark D. [CPhT, Ecole Polytechnique, Palaiseau (France)

    2013-11-07

    Light extra U(1) gauge bosons, so called hidden photons, which reside in a hidden sector have attracted much attention since they are a well motivated feature of many scenarios beyond the Standard Model and furthermore could mediate the interaction with hidden sector dark matter. We review limits on hidden photons from past electron beam dump experiments including two new limits from such experiments at KEK and Orsay. In addition, we study the possibility of having dark matter in the hidden sector. A simple toy model and different supersymmetric realisations are shown to provide viable dark matter candidates in the hidden sector that are in agreement with recent direct detection limits.

  13. Baryonic pinching of galactic dark matter halos

    SciTech Connect (OSTI)

    Gustafsson, Michael; Fairbairn, Malcolm; Sommer-Larsen, Jesper [Cosmology, Particle Astrophysics and String Theory, Department of Physics, Stockholm University, AlbaNova University Center, SE-106 91, Stockholm (Sweden); Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)

    2006-12-15

    High resolution cosmological N-body simulations of four galaxy-scale dark matter halos are compared to corresponding N-body/hydrodynamical simulations containing dark matter, stars and gas. The simulations without baryons share features with others described in the literature in that the dark matter density slope continuously decreases towards the center, with a density {rho}{sub DM}{proportional_to}r{sup -1.3{+-}}{sup 0.2}, at about 1% of the virial radius for our Milky Way sized galaxies. The central cusps in the simulations which also contain baryons steepen significantly, to {rho}{sub DM}{proportional_to}r{sup -1.9{+-}}{sup 0.2}, with an indication of the inner logarithmic slope converging. Models of adiabatic contraction of dark matter halos due to the central buildup of stellar/gaseous galaxies are examined. The simplest and most commonly used model, by Blumenthal et al., is shown to overestimate the central dark matter density considerably. A modified model proposed by Gnedin et al. is tested and it is shown that, while it is a considerable improvement, it is not perfect. Moreover, it is found that the contraction parameters in their model not only depend on the orbital structure of the dark-matter-only halos but also on the stellar feedback prescription which is most relevant for the baryonic distribution. Implications for dark matter annihilation at the galactic center are discussed and it is found that, although our simulations show a considerable reduced dark matter halo contraction as compared to the Blumenthal et al. model, the fluxes from dark matter annihilation are still expected to be enhanced by at least a factor of a hundred, as compared to dark-matter-only halos. Finally, it is shown that, while dark-matter-only halos are typically prolate, the dark matter halos containing baryons are mildly oblate with minor-to-major axis ratios of c/a=0.73{+-}0.11, with their flattening aligned with the central baryonic disks.

  14. Quintessence with quadratic coupling to dark matter

    SciTech Connect (OSTI)

    Boehmer, Christian G.; Chan, Nyein; Caldera-Cabral, Gabriela; Lazkoz, Ruth; Maartens, Roy

    2010-04-15

    We introduce a new form of coupling between dark energy and dark matter that is quadratic in their energy densities. Then we investigate the background dynamics when dark energy is in the form of exponential quintessence. The three types of quadratic coupling all admit late-time accelerating critical points, but these are not scaling solutions. We also show that two types of coupling allow for a suitable matter era at early times and acceleration at late times, while the third type of coupling does not admit a suitable matter era.

  15. Supersymmetric Dark Matter after LHC Run 1

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bagnaschi, E. A.; Buchmueller, O.; Cavanaugh, R.; Citron, M.; De Roeck, A.; Dolan, M. J.; Ellis, J. R.; Flacher, H.; Heinemeyer, S.; Isidori, G.; et al

    2015-10-23

    Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, ?~01, assumed here to be the lightest SUSY particle (LSP) and thus the dark matter (DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly degenerate next-to-lightest supersymmetric particle such as the lighter stau ?~1, stop t~1 or chargino ?~±1, resonant annihilation via direct-channel heavy Higgs bosons H / A, the light Higgs boson h or the Z boson, and enhanced annihilation via a larger Higgsino component of the LSP in the focus-pointmore »region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2, and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the ?~1 coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be explored at the LHC via searches for /ET events and long-lived charged particles, whereas theirH / A funnel, focus-point and ?~±1 coannihilation regions can largely be explored by the LZ and Darwin DM direct detection experiments. We find that the dominant DM mechanism in our pMSSM10 analysis is ?~±1 coannihilation: parts of its parameter space can be explored by the LHC, and a larger portion by future direct DM searches.« less

  16. Dynamics of dark energy in collapsing halo of dark matter

    E-Print Network [OSTI]

    Tsizh, M

    2015-01-01

    We investigate the non-linear evolution of spherical density and velocity perturbations of dark matter and dark energy in the expanding Universe. For that we have used the conservation and Einstein equations to describe the evolution of gravitationally coupled inhomogeneities of dark matter, dark energy and radiation from linear stage in the early Universe to the non-linear one at the current epoch. The simple method of the numerical integration of the system of non-linear differential equations for evolution of the central part of halo is proposed. The results are presented for halo of cluster ($k=2$ Mpc$^{-1}$) and supercluster scales ($k=0.2$ Mpc$^{-1}$) and show that quintessential scalar field dark energy with small value of effective speed of sound $c_s<0.1$ can give noticeable impact on the formation of large scale structures in the expanding Universe.

  17. Task I: Dark Matter Search Experiments with Cryogenic Detectors: CDMS-I and CDMS-II Task II: Experimental Study of Neutrino Properties: EXO and KamLAND

    SciTech Connect (OSTI)

    Cabrera, Blas [Professor, Stanford University] [Professor, Stanford University; Gratta, Giorgio [Professor, Stanford University] [Professor, Stanford University

    2013-08-30

    Dark Matter Search - During the period of performance, our group continued the search for dark matter in the form of weakly interacting massive particles or WIMPs. As a key member of the CDMS (Cryogenic Dark Matter Search) collaboration, we completed the CDMS II experiment which led the field in sensitivity for more than five years. We fabricated all detectors, and participated in detector testing and verification. In addition, we participated in the construction and operation of the facility at the Soudan Underground Laboratory and played key roles in the data acquisition and analysis. Towards the end of the performance period, we began operating the SuperCDMS Soudan experiment, which consists of 15 advanced Ge (9 kg) detectors. The advanced detector design called iZIP grew out of our earlier DOE Particle Detector R&D program which demonstrated the rejection of surface electrons to levels where they are no longer the dominant source of background. Our group invented this advanced design and these larger detectors were fabricated on the Stanford campus in collaboration with the SLAC CDMS group and the Santa Clara University group. The sensitivity reach is expected to be up to 5 times better than CDMS II after two years of operation. We will check the new limits on WIMPs set by XENON100, and we expect improved sensitivity for light mass WIMPs beyond that of any other existing experiment. Our group includes the Spokesperson for SuperCDMS and continues to make important contributions to improvements in the detector technology which are enabling the very low trigger thresholds used to explore the low mass WIMP region. We are making detailed measurements of the charge transport and trapping within Ge crystals, measuring the diffusive trapping distance of the quasiparticle excitations within the Al phonon collector fins on the detector surface, and we are contributing to the development of much improved detector Monte Carlos which are essential to guide the detector design and optimize the analysis. Neutrino Physics – In the period of performance the neutrino group successfully completed the construction of EXO-200 and commissioned the detector. Science data taking started on Jun 1, 2011. With the discovery of the 2-neutrino double-beta decay in 136-Xe and the first measurement of the 0-neutrino mode resulting in the most stringent limit of Majorana masses, our group continues to be a leading innovator in the field of neutrino physics which is central to DOE-HEP Intensity Frontier program. The phenomenon of neutrino oscillations, in part elucidated by our earlier efforts with the Palo Verde and KamLAND experiments, provides the crucial information that neutrino masses are non-zero and, yet, it contains no information on the value of the neutrino mass scale. In recent times our group has therefore shifted its focus to a high sensitivity 0-neutrino double beta decay program, EXO. The 0-neutrino double beta decay provides the best chance of extending the sensitivity to the neutrino mass scale below 10 meV but, maybe more importantly, it tests the nature of the neutrino wave function, providing the most sensitive probe for Majorana particles and lepton number violation. The EXO program, formulated by our group several years ago, plans to use up to tonnes of the isotope 136-Xe to study the 0-neutrino double beta decay mode. The EXO-200 detector is the first step in this program and it represents the only large US-led and based experiment taking data. The EXO-200 isotope enrichment program broke new grounds for the enterprise of double beta decay. The detector design and material selection program paid off, resulting in a background that is among the very best in the field. The “first light" of EXO-200 was very exciting with the discovery -in the first month of data- of the rarest 2-neutrino double beta decay mode ever observed. The lower limit on the 0-neutrino double beta decay half-life, published in Phys. Rev. Lett. and based on the first 120 days of data is the second best but, when translated into a Majorana mass scale, it

  18. Antigravitation, Dark Energy, Dark Matter - Alternative Solution

    E-Print Network [OSTI]

    Alexeev, Boris V

    2009-01-01

    Collisional damping of gravitational waves in the Newtonian matter is investigated. The generalized theory of Landau damping is applied to the gravitational physical systems in the context of the plasma gravitational analogy.

  19. Antigravitation, Dark Energy, Dark Matter - Alternative Solution

    E-Print Network [OSTI]

    Boris V. Alexeev

    2009-09-04

    Collisional damping of gravitational waves in the Newtonian matter is investigated. The generalized theory of Landau damping is applied to the gravitational physical systems in the context of the plasma gravitational analogy.

  20. Contamination of Dark Matter Experiments from Atmospheric Magnetic Dipoles

    E-Print Network [OSTI]

    A. Bueno; M. Masip; P. Sánchez-Lucas; N. Setzer

    2013-10-14

    Dark matter collisions with heavy nuclei (Xe, Ge, Si, Na) may produce recoils observable at direct-search experiments. Given that some of these experiments are yielding conflicting information, however, it is worth asking if physics other than dark matter may produce similar nuclear recoils. We examine under what conditions an atmospherically-produced neutral particle with a relatively large magnetic dipole moment could fake a dark matter signal. We argue that a very definite flux could explain the signals seen at DAMA/LIBRA, CDMS/Si and CoGeNT consistently with the bounds from XENON100 and CDMS/Ge. To explore the plausibility of this scenario, we discuss a concrete model with 10-50 MeV sterile neutrinos that was recently proposed to explain the LSND and MiniBooNE anomalies.

  1. Superheavy sterile neutrinos as dark matter 

    E-Print Network [OSTI]

    Tang, Yongjun

    2000-01-01

    neutrinos as a dark matter candidate, produced through MSW conversion of active neutrinos. Recently Allen proposed a different nonthermal mechanism for the production of superheavy sterile neutrinos. Such neutrinos are predicted by an SO(10) grand...

  2. Disentangling Dark Matter Dynamics with Directional Detection

    SciTech Connect (OSTI)

    Lisanti, Mariangela; Wacker, Jay G.; /SLAC

    2009-12-16

    Inelastic dark matter reconciles the DAMA anomaly with other null direct detection experiments and points to a non-minimal structure in the dark matter sector. In addition to the dominant inelastic interaction, dark matter scattering may have a subdominant elastic component. If these elastic interactions are suppressed at low momentum transfer, they will have similar nuclear recoil spectra to inelastic scattering events. While upcoming direct detection experiments will see strong signals from such models, they may not be able to unambiguously determine the presence of the subdominant elastic scattering from the recoil spectra alone. We show that directional detection experiments can separate elastic and inelastic scattering events and discover the underlying dynamics of dark matter models.

  3. Shocking Signals of Dark Matter Annihilation

    E-Print Network [OSTI]

    Davis, Jonathan H; Boehm, Celine; Kotera, Kumiko; Norman, Colin

    2015-01-01

    We examine whether charged particles injected by self-annihilating Dark Matter into regions undergoing Diffuse Shock Acceleration (DSA) can be accelerated to high energies. We consider three astrophysical sites where shock acceleration is supposed to occur, namely the Galactic Centre, galaxy clusters and Active Galactic Nuclei (AGN). For the Milky Way, we find that the acceleration of cosmic rays injected by dark matter could lead to a bump in the cosmic ray spectrum provided that the product of the efficiency of the acceleration mechanism and the concentration of DM particles is high enough. Among the various acceleration sources that we consider (namely supernova remnants (SNRs), Fermi bubbles and AGN jets), we find that the Fermi bubbles are a potentially more efficient accelerator than SNRs. However both could in principle accelerate electrons and protons injected by dark matter to very high energies. At the extragalactic level, the acceleration of dark matter annihilation products could be responsible fo...

  4. Scalar Dark Matter From Theory Space

    SciTech Connect (OSTI)

    Birkedal-Hansen, Andreas; Wacker, Jay G.

    2003-12-26

    The scalar dark matter candidate in a prototypical theory space little Higgs model is investigated. We review all details of the model pertinent to a relic density calculation. We perform a thermal relic density calculation including couplings to the gauge and Higgs sectors of the model. We find two regions of parameter space that give acceptable dark matter abundances. The first region has a dark matter candidate with a mass {Omicron}(100 GeV), the second region has a candidate with a mass greater than {Omicron}(500 GeV). The dark matter candidate in either region is an admixture of an SU(2) triplet and an SU(2) singlet, thereby constituting a possible WIMP (weakly interacting massive particle).

  5. Light Dark Matter Annihilations into Two Photons

    E-Print Network [OSTI]

    C. Boehm; J. Orloff; P. Salati

    2006-07-19

    We compute the pair annihilation cross section of light (spin-0) dark matter particles into two photons and discuss the detectability of the monochromatic line associated with these annihilations.

  6. Scalar Dark Matter: Direct vs. Indirect Detection

    E-Print Network [OSTI]

    Michael Duerr; Pavel Fileviez Perez; Juri Smirnov

    2015-09-14

    We revisit the simplest model for dark matter. In this context the dark matter candidate is a real scalar field which interacts with the Standard Model particles through the Higgs portal. We discuss the relic density constraints as well as the predictions for direct and indirect detection. The final state radiation processes are investigated in order to understand the visibility of the gamma lines from dark matter annihilation. We find two regions where one could observe the gamma lines at gamma-ray telescopes. We point out that the region where the dark matter mass is between 100 and 300 GeV can be tested in the near future at direct and indirect detection experiments.

  7. Scalar Dark Matter: Direct vs. Indirect Detection

    E-Print Network [OSTI]

    Duerr, Michael; Smirnov, Juri

    2015-01-01

    We revisit the simplest model for dark matter. In this context the dark matter candidate is a real scalar field which interacts with the Standard Model particles through the Higgs portal. We discuss the relic density constraints as well as the predictions for direct and indirect detection. The final state radiation processes are investigated in order to understand the visibility of the gamma lines from dark matter annihilation. We find two regions where one could observe the gamma lines at gamma-ray telescopes. We point out that the region where the dark matter mass is between 100 and 300 GeV can be tested in the near future at direct and indirect detection experiments.

  8. On The Origin of Light Dark Matter Species

    SciTech Connect (OSTI)

    Essig, Rouven; Kaplan, Jared; Schuster, Philip; /SLAC; Toro, Natalia; /Stanford U., Phys. Dept.

    2010-06-04

    TeV-mass dark matter charged under a new GeV-scale gauge force can explain electronic cosmic-ray anomalies. We propose that the CoGeNT and DAMA direct detection experiments are observing scattering of light stable states 'GeV-Matter' that are charged under this force and constitute a small fraction of the dark matter halo. Dark higgsinos in a supersymmetric dark sector are natural candidates for GeV-Matter that scatter off protons with a universal cross-section of 5 x 10{sup -38} cm{sup 2} and can naturally be split by 10-30 keV so that their dominant interaction with protons is down-scattering. As an example, down-scattering of an O(5) GeV dark higgsino can simultaneously explain the spectra observed by both CoGeNT and DAMA. The event rates in these experiments correspond to a GeV-Matter abundance of 0.2-1% of the halo mass density. This abundance can arise directly from thermal freeze-out at weak coupling, or from the late decay of an unstable TeV-scale WIMP. Our proposal can be tested by searches for exotics in the BaBar and Belle datasets.

  9. A taste of dark matter: Flavour constraints on pseudoscalar mediators

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dolan, Matthew J.; Kahlhoefer, Felix; McCabe, Christopher; Schmidt-Hoberg, Kai

    2015-03-31

    Dark matter interacting via the exchange of a light pseudoscalar can induce observable signals in indirect detection experiments and experience large self-interactions while evading the strong bounds from direct dark matter searches. The pseudoscalar mediator will however induce flavour-changing interactions in the Standard Model, providing a promising alternative way to test these models. We investigate in detail the constraints arising from rare meson decays and fixed target experiments for different coupling structures between the pseudoscalar and Standard Model fermions. The resulting bounds are highly complementary to the information inferred from the dark matter relic density and the constraints from primordialmore »nucleosynthesis. We discuss the implications of our findings for the dark matter self-interaction cross section and the prospects of probing dark matter coupled to a light pseudoscalar with direct or indirect detection experiments. In particular, we find that a pseudoscalar mediator can only explain the Galactic Centre excess if its mass is above that of the B mesons, and that it is impossible to obtain a sufficiently large direct detection cross section to account for the DAMA modulation.« less

  10. Dark Matter Through the Neutrino Portal

    E-Print Network [OSTI]

    Adam Falkowski; Jose Juknevich; Jessie Shelton

    2009-08-13

    We consider a model of dark matter whose most prominent signature is a monochromatic flux of TeV neutrinos from the galactic center. As an example of a general scenario, we consider a specific model where the dark matter is a fermion in the adjoint representation of a hidden SU(N) gauge group that confines at GeV energies. The absence of light fermionic states in the dark sector ensures stability of dark matter on cosmological time scales. Dark matter couples to the standard model via the neutrino portal, that is, the singlet operator H L constructed from the Higgs and lepton doublets, which is the lowest dimensional fermionic singlet operator in the standard model. This coupling prompts dark matter decay where the dominant decay channel has one neutrino (and at least one dark glueball) in the final state. Other decay channels with charged standard model particles involve more particles in the final state and are therefore suppressed by phase space. In consequence, the standard indirect detection signals like gamma-ray photons, antiprotons and positrons are suppressed with respect to the neutrino signal. This coupling via the neutrino portal is most robustly constrained by Super-Kamiokande, which restricts the dark matter lifetime to be larger than 10^25 seconds. In the near future, the scenario will be probed by the new generation of neutrino telescopes. ANTARES will be sensitive to a dark matter lifetime of order 10^26 seconds, while IceCube/DeepCore can probe a lifetime as large as 10^27 seconds.

  11. LIGHT PHOTINOS AS DARK MATTER

    E-Print Network [OSTI]

    Glennys R. Farrar; Edward W. Kolb

    1995-04-24

    There are good reasons to consider models of low-energy supersymmetry with very light photinos and gluinos. In a wide class of models the lightest $R$-odd, color-singlet state containing a gluino, the $\\r0$, has a mass in the 1-2 GeV range and the slightly lighter photino, $\\pho$, would survive as the relic $R$-odd species. For the light photino masses considered here, previous calculations resulted in an unacceptable photino relic abundance. But we point out that processes other than photino self-annihilation determine the relic abundance when the photino and $R^0$ are close in mass. Including $\\r0\\longleftrightarrow\\pho$ processes, we find that the photino relic abundance is most sensitive to the $\\r0$-to-$\\pho$ mass ratio, and within model uncertainties, a critical density in photinos may be obtained for an $\\r0$-to-$\\pho$ mass ratio in the range 1.2 to 2.2. We propose photinos in the mass range of 500 MeV to 1.6 GeV as a dark matter candidate, and discuss a strategy to test the hypothesis.

  12. Photonic dark matter portal revisited

    E-Print Network [OSTI]

    S. A. Alavi; F S Kazemian

    2015-11-18

    In our previous paper [1], we studied a model of dark matter (DM) in which the hidden sector interacts with standard model particles via a hidden photonic portal (HP). We investigated the effects of this new interaction on the hydrogen atom and obtained an upper bound for the coupling of the model. In this work, we study the effects of HP on two interesting exotic atoms namely muonium and positronium. We obtain a tighter upper limit on the coupling. We also calculate the change (shift) in the Aharonov-Bohm phase due to HP and find that the phase shift is negligibly small (for DM particles mass in the GeV range). Recently a 3.5 keV X ray line signal observed in the spectrum of 73 galaxy clusters, reported by the XXM-Newton X ray observatory. Since in HP model the DM particles can decay directly into photons, so we finally calculate the value of the coupling constant f using the condition Delta E=3.5 keV.

  13. Dark matter burners: Preliminary estimates

    E-Print Network [OSTI]

    I. V. Moskalenko; L. L. Wai

    2007-02-24

    We show that a star orbiting close enough to an adiabatically grown supermassive black hole can capture a large number of weakly interacting massive particles (WIMPs) during its lifetime. WIMP annihilation energy release in low- to medium-mass stars is comparable with or even exceeds the luminosity of such stars due to thermonuclear burning. The excessive energy release in the stellar core may result in an evolution scenario different from what is expected for a regular star. The model thus predicts the existence of unusual stars within the central parsec of galactic nuclei. If found, such stars would provide evidence for the existence of particle dark matter. White dwarfs seem to be the most promising candidates to look for. The signature of a white dwarf burning WIMPs would be a very hot star with mass and radius characteristic for a white dwarf, but with luminosity exceeding the typical luminosity of a white dwarf by orders of magnitude <50L_sun. A white dwarf with a highly eccentric orbit around the central black hole may exhibit variations in brightness correlated with the orbital phase.

  14. Dark Matter Triggers of Supernovae

    E-Print Network [OSTI]

    Graham, Peter W; Varela, Jaime

    2015-01-01

    The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to $1.25 M_{\\odot}$ rules out primordial black holes with masses $\\sim 10^{19}$ gm - $10^{20}$ gm as a dominant constituent of the local dark matter density. Black holes with masses as large as $10^{24}$ gm will be excluded if recent observations by the NuStar collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range $10^{20}$ gm - $10^{22}$ gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism p...

  15. Dark matter directional detection in non-relativistic effective theories

    E-Print Network [OSTI]

    Catena, Riccardo

    2015-01-01

    We extend the formalism of dark matter directional detection to arbitrary one-body dark matter-nucleon interactions. The new theoretical framework generalizes the one currently used, which is based on 2 types of dark matter-nucleon interaction only. It includes 14 dark matter-nucleon interaction operators, 8 isotope-dependent nuclear response functions, and the Radon transform of the first 2 moments of the dark matter velocity distribution. We calculate the recoil energy spectra at dark matter directional detectors made of CF$_4$, CS$_2$ and $^{3}$He for the 14 dark matter-nucleon interactions, using nuclear response functions recently obtained through numerical nuclear structure calculations. We highlight the new features of the proposed theoretical framework, and present our results for a spherical dark matter halo and for a stream of dark matter particles. This study lays the foundations for model independent analyses of dark matter directional detection experiments.

  16. Dark matter directional detection in non-relativistic effective theories

    E-Print Network [OSTI]

    Riccardo Catena

    2015-05-24

    We extend the formalism of dark matter directional detection to arbitrary one-body dark matter-nucleon interactions. The new theoretical framework generalizes the one currently used, which is based on 2 types of dark matter-nucleon interaction only. It includes 14 dark matter-nucleon interaction operators, 8 isotope-dependent nuclear response functions, and the Radon transform of the first 2 moments of the dark matter velocity distribution. We calculate the recoil energy spectra at dark matter directional detectors made of CF$_4$, CS$_2$ and $^{3}$He for the 14 dark matter-nucleon interactions, using nuclear response functions recently obtained through numerical nuclear structure calculations. We highlight the new features of the proposed theoretical framework, and present our results for a spherical dark matter halo and for a stream of dark matter particles. This study lays the foundations for model independent analyses of dark matter directional detection experiments.

  17. Cosmological effects of coupled dark matter

    E-Print Network [OSTI]

    Sophie C. F. Morris; Anne M. Green; Antonio Padilla; Ewan R. M. Tarrant

    2013-10-15

    Many models have been studied that contain more than one species of dark matter and some of these couple the Cold Dark Matter (CDM) to a light scalar field. In doing this we introduce additional long range forces, which in turn can significantly affect our estimates of cosmological parameters if not properly accounted for. It is, therefore, important to study these models and their resulting cosmological implications. We present a model in which a fraction of the total cold dark matter density is coupled to a scalar field. We study the background and perturbation evolution and calculate the resulting Cosmic Microwave Background anisotropy spectra. The greater the fraction of dark matter coupled to the scalar field and the stronger the coupling strength, the greater the deviation of the background evolution from LCDM. Previous work, with a single coupled dark matter species, has found an upper limit on the coupling strength of order O(0.1). We find that with a coupling of this magnitude more than half the dark matter can be coupled to a scalar field without producing any significant deviations from LCDM.

  18. Measuring the dark matter equation of state

    E-Print Network [OSTI]

    Ana Laura Serra; Mariano Javier de León Domínguez Romero

    2011-05-30

    The nature of the dominant component of galaxies and clusters remains unknown. While the astrophysics community supports the cold dark matter (CDM) paradigm as a clue factor in the current cosmological model, no direct CDM detections have been performed. Faber and Visser 2006 have suggested a simple method for measuring the dark matter equation of state that combines kinematic and gravitational lensing data to test the widely adopted assumption of pressureless dark matter. Following this formalism, we have measured the dark matter equation of state for first time using improved techniques. We have found that the value of the equation of state parameter is consistent with pressureless dark matter within the errors. Nevertheless, the measured value is lower than expected because typically the masses determined with lensing are larger than those obtained through kinematic methods. We have tested our techniques using simulations and we have also analyzed possible sources of error that could invalidate or mimic our results. In the light of this result, we can now suggest that the understanding of the nature of dark matter requires a complete general relativistic analysis.

  19. A Window in the Dark Matter Exclusion Limits

    E-Print Network [OSTI]

    Gabrijela Zaharijas; Glennys R. Farrar

    2005-06-28

    We consider the cross section limits for light dark matter candidates ($m=0.4$ to 10 GeV). We calculate the interaction of dark matter in the crust above underground dark matter detectors and find that in the intermediate cross section range, the energy loss of dark matter is sufficient to fall below the energy threshold of current underground experiments. This implies the existence of a window in the dark matter exclusion limits in the micro-barn range.

  20. Spectral Gamma-ray Signatures of Cosmological Dark Matter Annihilation

    E-Print Network [OSTI]

    Lars Bergstrom; Joakim Edsjo; Piero Ullio

    2001-12-13

    We propose a new signature for weakly interacting massive particle (WIMP) dark matter, a spectral feature in the diffuse extragalactic gamma-ray radiation. This feature, a sudden drop of the gamma-ray intensity at an energy corresponding to the WIMP mass, comes from the asymmetric distortion of the line due to WIMP annihilation into two gamma-rays caused by the cosmological redshift. Unlike other proposed searches for a line signal, this method is not very sensitive to the exact dark matter density distribution in halos and subhalos. The only requirement is that the mass distribution of substructure on small scales follows approximately the Press-Schechter law, and that smaller halos are on the average denser than large halos, which is a generic outcome of N-body simulations of Cold Dark Matter, and which has observational support. The upcoming Gamma-ray Large Area Space Telescope (GLAST) will be eminently suited to search for these spectral features. For numerical examples, we use rates computed for supersymmetric particle dark matter, where a detectable signal is possible.

  1. Higgs portal dark matter in the minimal gauged $U(1)_{B-L}$ model

    E-Print Network [OSTI]

    Nobuchika Okada; Osamu Seto

    2010-02-13

    We propose a scenario of the right-handed neutrino dark matter in the context of the minimal gauged $U(1)_{B-L}$ model by introducing an additional parity which ensures the stability of dark matter particle. The annihilation of this right-handed neutrino takes place dominantly through the s-channel Higgs boson exchange, so that this model can be called Higgs portal dark matter model. We show that the thermal relic abundance of the right-handed neutrino dark matter with help of Higgs resonance can match the observed dark matter abundance. In addition we estimate the cross section with nucleon and show that the next generation direct dark matter search experiments can explore this model.

  2. Dark matter and dark energy from quark bag model

    SciTech Connect (OSTI)

    Brilenkov, Maxim; Eingorn, Maxim; Jenkovszky, Laszlo; Zhuk, Alexander E-mail: maxim.eingorn@gmail.com E-mail: ai.zhuk2@gmail.com

    2013-08-01

    We calculate the present expansion of our Universe endowed with relict colored objects — quarks and gluons — that survived hadronization either as isolated islands of quark-gluon ''nuggets'' or spread uniformly in the Universe. In the first scenario, the QNs can play the role of dark matter. In the second scenario, we demonstrate that uniform colored objects can play the role of dark energy providing the late-time accelerating expansion of the Universe.

  3. Thermodynamics of dark energy interacting with dark matter and radiation

    E-Print Network [OSTI]

    Mubasher Jamil; Emmanuel N. Saridakis; M. R. Setare

    2010-07-18

    We investigate the validity of the generalized second law of thermodynamics, in the cosmological scenario where dark energy interacts with both dark matter and radiation. Calculating separately the entropy variation for each fluid component and for the apparent horizon itself, we show that the generalized second law is always and generally valid, independently of the specific interaction form, of the fluids equation-of-state parameters and of the background geometry.

  4. The Unification and Cogeneration of Dark Matter and Baryonic Matter

    E-Print Network [OSTI]

    S. M. Barr

    2011-09-18

    In grand unified theories with gauge groups larger than SU(5), the multiplets that contain the known quarks and leptons also contain fermions that are singlets under the Standard Model gauge group. Some of these could be the dark matter of the universe. Grand unified theories can also have accidental U(1) global symmetries (analogous to B-L in minimal SU(5)) that can stabilize dark matter. These ideas are illustrated in an SU(6) model.

  5. The Unification and Cogeneration of Dark Matter and Baryonic Matter

    E-Print Network [OSTI]

    Barr, S M

    2011-01-01

    In grand unified theories with gauge groups larger than SU(5), the multiplets that contain the known quarks and leptons also contain fermions that are singlets under the Standard Model gauge group. Some of these could be the dark matter of the universe. Grand unified theories can also have accidental U(1) global symmetries (analogous to B-L in minimal SU(5)) that can stabilize dark matter. These ideas are illustrated in an SU(6) model.

  6. Fluid Mechanics Explains Cosmology, Dark Matter, Dark Energy, and Life

    E-Print Network [OSTI]

    Carl H. Gibson

    2012-11-02

    Observations of the interstellar medium by the Herschel, Planck etc. infrared satellites throw doubt on standard {\\Lambda}CDMHC cosmological processes to form gravitational structures. According to the Hydro-Gravitational-Dynamics (HGD) cosmology of Gibson (1996), and the quasar microlensing observations of Schild (1996), the dark matter of galaxies consists of Proto-Globular-star-Cluster (PGC) clumps of Earth-mass primordial gas planets in metastable equilibrium since PGCs began star production at 0.3 Myr by planet mergers. Dark energy and the accelerating expansion of the universe inferred from SuperNovae Ia are systematic dimming errors produced as frozen gas dark matter planets evaporate to form stars. Collisionless cold dark matter that clumps and hierarchically clusters does not exist. Clumps of PGCs began diffusion from the Milky Way Proto-Galaxy upon freezing at 14 Myr to give the Magellanic Clouds and the faint dwarf galaxies of the 10^22 m diameter baryonic dark matter Galaxy halo. The first stars persist as old globular star clusters (OGCs). Water oceans and the biological big bang occurred at 2-8 Myr. Life inevitably formed and evolved in the cosmological primordial organic soup provided by 10^80 big bang planets and their hot oceans as they gently merged to form larger binary planets and small binary stars.

  7. Dark Energy and Dark Matter in Stars Physic

    E-Print Network [OSTI]

    Plamen Fiziev

    2014-11-02

    We present the basic equations and relations for the relativistic static spherically symmetric stars (SSSS) in the model of minimal dilatonic gravity (MDG) which is {\\em locally} equivalent to the f(R) theories of gravity and gives an alternative description of the effects of dark matter and dark energy. The results for the simplest form of the relativistic equation of state (EOS) of neutron matter are represented. Our approach overcomes the well-known difficulties of the physics of SSSS in the f(R) theories of gravity introducing two novel EOS for cosmological energy-pressure densities and dilaton energy-pressure densities, as well as proper boundary conditions.

  8. Results on light dark matter particles with a low-threshold CRESST-II detector

    E-Print Network [OSTI]

    Angloher, G; Bucci, C; Canonica, L; Defay, X; Erb, A; Feilitzsch, F v; Iachellini, N Ferreiro; Gorla, P; Gütlein, A; Hauff, D; Jochum, J; Kiefer, M; Kluck, H; Kraus, H; Lanfranchi, J C; Loebell, J; Münster, A; Pagliarone, C; Petricca, F; Potzel, W; Pröbst, F; Reindl, F; Schäffner, K; Schieck, J; Schönert, S; Seidel, W; Stodolsky, L; Strandhagen, C; Strauss, R; Tanzke, A; Thi, H H Trinh; Türko?lu, C; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wüstrich, M; Zöller, A

    2015-01-01

    The CRESST-II experiment uses cryogenic detectors to search for nuclear recoil events induced by the elastic scattering of dark matter particles in CaWO$_4$ crystals. Given the low energy threshold of our detectors in combination with light target nuclei, low mass dark matter particles can be probed with high sensitivity. In this letter we present the results from data of a single detector module corresponding to 52 kg live days. A blind analysis is carried out. With an energy threshold for nuclear recoils of 307 eV we substantially enhance the sensitivity for light dark matter. Thereby, we extend the reach of direct dark matter experiments to the sub-region and demonstrate that the energy threshold is the key parameter in the search for low mass dark matter particles.

  9. Direct Detection of Cold Dark Matter

    E-Print Network [OSTI]

    Laura Baudis

    2007-11-25

    We know from cosmological and astrophysical observations that more than 80% of the matter density in the Universe is non-luminous, or dark. This non-baryonic dark matter could be composed of neutral, heavy particles, which were non-relativistic, or 'cold', when they decoupled from ordinary matter. I will review the direct detection methods of these hypothetical particles via their interactions with nuclei in ultra-low background, deep underground experiments. The emphasis is on most recent results and on the status of near future projects.

  10. Dissipative dark matter and the rotation curves of dwarf galaxies

    E-Print Network [OSTI]

    Foot, R

    2015-01-01

    There is ample evidence from rotation curves that dark matter halo's around disk galaxies have nontrivial dynamics. Of particular significance are: a) the cored dark matter profile of disk galaxies, b) correlations of the shape of rotation curves with baryonic properties, and c) the Tully-Fisher relation. Dark matter halo's around disk galaxies may have nontrivial dynamics if dark matter is strongly self interacting and dissipative. Multicomponent hidden sector dark matter featuring a massless `dark photon' (from an unbroken dark $U(1)$ gauge interaction) which kinetically mixes with the ordinary photon provides a concrete example of such dark matter. The kinetic mixing interaction facilitates halo heating by enabling ordinary supernovae to be a source of these `dark photons'. Dark matter halo's can expand and contract in response to the heating and cooling processes, but for a sufficiently isolated halo should have evolved to a steady state or `equilibrium' configuration where heating and cooling rates local...

  11. Cold Positrons from Decaying Dark Matter

    SciTech Connect (OSTI)

    Boubekeur, Lotfi; Dodelson, Scott; Vives, Oscar

    2012-11-01

    Many models of dark matter contain more than one new particle beyond those in the Standard Model. Often heavier particles decay into the lightest dark matter particle as the Universe evolves. Here we explore the possibilities that arise if one of the products in a (Heavy Particle) $\\rightarrow$ (Dark Matter) decay is a positron, and the lifetime is shorter than the age of the Universe. The positrons cool down by scattering off the cosmic microwave background and eventually annihilate when they fall into Galactic potential wells. The resulting 511 keV flux not only places constraints on this class of models but might even be consistent with that observed by the INTEGRAL satellite.

  12. Neutralino Dark Matter in BMSSM Effective Theory

    E-Print Network [OSTI]

    Marcus Berg; Joakim Edsjo; Paolo Gondolo; Erik Lundstrom; Stefan Sjors

    2009-06-03

    We study thermal neutralino dark matter in an effective field theory extension of the MSSM, called "Beyond the MSSM" (BMSSM) in Dine, Seiberg and Thomas (2007). In this class of effective field theories, the field content of the MSSM is unchanged, but the little hierarchy problem is alleviated by allowing small corrections to the Higgs/higgsino part of the Lagrangian. We perform parameter scans and compute the dark matter relic density. The light Higgsino LSP scenario is modified the most; we find new regions of parameter space compared to the standard MSSM. This involves interesting interplay between the WMAP dark matter bounds and the LEP chargino bound. We also find some changes for gaugino LSPs, partly due to annihilation through a Higgs resonance, and partly due to coannihilation with light stops in models that are ruled in by the new effective terms.

  13. Neutralino dark matter in BMSSM effective theory

    SciTech Connect (OSTI)

    Berg, Marcus; Edsjö, Joakim; Lundström, Erik; Sjörs, Stefan; Gondolo, Paolo E-mail: edsjo@physto.se E-mail: erik@physto.se

    2009-08-01

    We study thermal neutralino dark matter in an effective field theory extension of the MSSM, called ''Beyond the MSSM'' (BMSSM) in Dine, Seiberg and Thomas (2007). In this class of effective field theories, the field content of the MSSM is unchanged, but the little hierarchy problem is alleviated by allowing small corrections to the Higgs/higgsino part of the Lagrangian. We perform parameter scans and compute the dark matter relic density. The light higgsino LSP scenario is modified the most; we find new regions of parameter space compared to the standard MSSM. This involves interesting interplay between the WMAP dark matter bounds and the LEP chargino bound. We also find some changes for gaugino LSPs, partly due to annihilation through a Higgs resonance, and partly due to coannihilation with light top squarks in models that are ruled in by the new effective terms.

  14. A generic method to constrain the dark matter model parameters from Fermi observations of dwarf spheroids

    SciTech Connect (OSTI)

    Tsai, Yue-Lin Sming [National Center for Nuclear Research, Hoza 69, 00-681 Warsaw (Poland); Yuan, Qiang [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, P.R.China (China); Huang, Xiaoyuan, E-mail: Sming.Tsai@fuw.edu.pl, E-mail: yuanq@ihep.ac.cn, E-mail: x_huang@bao.ac.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, P.R.China (China)

    2013-03-01

    Observation of ?-rays from dwarf galaxies is an effective way to search for particle dark matter. Using 4-year data of Fermi-LAT observations on a series of Milky Way satellites, we develop a general way to search for the signals from dark matter annihilation in such objects. Instead of giving prior information about the energy spectrum of dark matter annihilation, we bin the Fermi-LAT data into several energy bins and build a likelihood map in the ''energy bin - flux'' plane. The final likelihood of any spectrum can be easily derived through combining the likelihood of all the energy bins. It gives consistent result with that directly calculated using the Fermi Scientific Tool. This method is very efficient for the study of any specific dark matter models with ?-rays. We use the new likelihood map with Fermi-LAT 4 year data to fit the parameter space in three representative dark matter models: i) toy dark matter model, ii) effective dark matter operators, and iii) supersymmetric neutralino dark matter.

  15. Form factors for dark matter capture by the Sun in effective theories

    E-Print Network [OSTI]

    Riccardo Catena; Bodo Schwabe

    2015-07-17

    In the effective theory of isoscalar and isovector dark matter-nucleon interactions mediated by a heavy spin-1 or spin-0 particle, 8 isotope-dependent nuclear response functions can be generated in the dark matter scattering by nuclei. We compute the 8 nuclear response functions for the 16 most abundant elements in the Sun, i.e. H, $^{3}$He, $^{4}$He, $^{12}$C, $^{14}$N, $^{16}$O, $^{20}$Ne, $^{23}$Na, $^{24}$Mg, $^{27}$Al, $^{28}$Si, $^{32}$S, $^{40}$Ar, $^{40}$Ca, $^{56}$Fe, and $^{59}$Ni, through numerical shell model calculations. We use our response functions to compute the rate of dark matter capture by the Sun for all isoscalar and isovector dark matter-nucleon effective interactions, including several operators previously considered for dark matter direct detection only. We study in detail the dependence of the capture rate on specific dark matter-nucleon interaction operators, and on the different elements in the Sun. We find that a so far neglected momentum dependent dark matter coupling to the nuclear vector charge gives a larger contribution to the capture rate than the constant spin-dependent interaction commonly included in dark matter searches at neutrino telescopes. Our investigation lays the foundations for model independent analyses of dark matter induced neutrino signals from the Sun. The nuclear response functions obtained in this study are listed in analytic form in an appendix, ready to be used in other projects.

  16. Review of the theoretical and experimental status of dark matter identification with cosmic-ray antideuterons

    E-Print Network [OSTI]

    Aramaki, T; Bufalino, S; Dal, L; von Doetinchem, P; Donato, F; Fornengo, N; Fuke, H; Grefe, M; Hailey, C; Hamilton, B; Ibarra, A; Mitchell, J; Mognet, I; Ong, R A; Pereira, R; Perez, K; Putze, A; Raklev, A; Salati, P; Sasaki, M; Tarle, G; Urbano, A; Vittino, A; Wild, S; Xue, W; Yoshimura, K

    2015-01-01

    Recent years have seen increased theoretical and experimental effort towards the first-ever detection of cosmic-ray antideuterons, in particular as an indirect signature of dark matter annihilation or decay. In contrast to indirect dark matter searches using positrons, antiprotons, or gamma-rays, which suffer from relatively high and uncertain astrophysical backgrounds, searches with antideuterons benefit from very suppressed conventional backgrounds, offering a potential breakthrough in unexplored phase space for dark matter. This article is based on the first dedicated cosmic-ray antideuteron workshop, which was held at UCLA in June 2014. It reviews broad classes of dark matter candidates that result in detectable cosmic-ray antideuteron fluxes, as well as the status and prospects of current experimental searches. The coalescence model of antideuteron production and the influence of antideuteron measurements at particle colliders are discussed. This is followed by a review of the modeling of antideuteron pr...

  17. Anti-helium from Dark Matter annihilations

    E-Print Network [OSTI]

    Marco Cirelli; Nicolao Fornengo; Marco Taoso; Andrea Vittino

    2014-10-21

    Galactic Dark Matter (DM) annihilations can produce cosmic-ray anti-nuclei via the nuclear coalescence of the anti-protons and anti-neutrons originated directly from the annihilation process. Since anti-deuterons have been shown to offer a distinctive DM signal, with potentially good prospects of detection in large portions of the DM-particle parameter space, we explore here the production of heavier anti-nuclei, specifically anti-helium. Even more than for anti-deuterons, the DM-produced anti-He flux can be mostly prominent over the astrophysical anti-He background at low kinetic energies, typically below 3-5 GeV/n. However, the larger number of anti-nucleons involved in the formation process makes the anti-He flux extremely small. We therefore explore, for a few DM benchmark cases, whether the yield is sufficient to allow for anti-He detection in current-generation experiments, such as AMS-02. We account for the uncertainties due to the propagation in the Galaxy and to the uncertain details of the coalescence process, and we consider the constraints already imposed by anti-proton searches. We find that only for very optimistic configurations it might be possible to achieve detection with current generation detectors. We estimate that, in more realistic configurations, an increase in experimental sensitivity at low-kinetic energies of about a factor of 500-1000 would allow to start probing DM through the rare cosmic anti-He production.

  18. A SM Singlet Scalar as Dark Matter

    E-Print Network [OSTI]

    Tonatiuh Matos; Ricardo Lopez-Fernandez

    2014-03-20

    In this work we investigate the possibility that a simple extension of the Standard Model (SM) can be the dark matter of the universe. We postulate the existence of a scalar field singlet like the Higgs as an extra term in the SM Lagrangian. We find that from the astrophysical point of view a very small mass and self-interaction is more convenient to agree with observations and from particle detectors observations we do not see any essential constrain to this settings. Thus, we conclude that a scalar field singlet with a small mass and self-interaction is a good candidate to be the nature of the dark matter.

  19. Axions as hot and cold dark matter

    SciTech Connect (OSTI)

    Jeong, Kwang Sik; Kawasaki, Masahiro; Takahashi, Fuminobu E-mail: kawasaki@icrr.u-tokyo.ac.jp

    2014-02-01

    The presence of a hot dark matter component has been hinted at 3? by a combination of the results from different cosmological observations. We examine a possibility that pseudo Nambu-Goldstone bosons account for both hot and cold dark matter components. We show that the QCD axions can do the job for the axion decay constant f{sub a}?

  20. Asymmetric dark matter and the Sun

    E-Print Network [OSTI]

    Mads T. Frandsen; Subir Sarkar

    2010-06-01

    Cold dark matter particles with an intrinsic matter-antimatter asymmetry do not annihilate after gravitational capture by the Sun and can affect its interior structure. The rate of capture is exponentially enhanced when such particles have self-interactions of the right order to explain structure formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural candidate and has the required relic abundance if its asymmetry is similar to that of ordinary baryons. We show that such particles can solve the `solar composition problem'. The predicted small decrease in the low energy neutrino fluxes may be measurable by the Borexino and SNO+ experiments.

  1. Understanding the Fundamental Properties of Dark Matter and Dark Energy in Structure Formation and Cosmology

    SciTech Connect (OSTI)

    Ellis, Richard S.

    2012-09-30

    The program was concerned with developing and verifying the validity of observational methods for constraining the properties of dark matter and dark energy in the Universe.

  2. Complementarity of direct dark matter detection and indirect detection through gamma-rays

    E-Print Network [OSTI]

    Lars Bergstrom; Torsten Bringmann; Joakim Edsjo

    2011-02-23

    We show, by using an extensive sample of viable supersymmetric models as templates, that indirect detection of dark matter through gamma rays may have a large potential for identifying the nature of dark matter. This is in particular true also for models that give too weak dark matter-nucleon scattering cross sections to be probed by present and planned direct detection experiments. Also models with a mass scale too high to be accessible at CERN's LHC accelerator may show up in next-generation imaging Cherenkov telescope arrays. Based on our our findings, we therefore suggest to view indirect searches as genuine particle physics experiments, complementing other strategies to probe so far unknown regions in the parameter space of e.g. supersymmetric models, and propose a new approach that would make use of telescopes dedicated for dark matter searches. As a concrete example for the potential of such an approach, we consider an array of imaging air Cherenkov telescopes, the Dark Matter Array (DMA), and show that such an experiment could extend present-day limits by several orders of magnitude, reaching a large class of models that would remain undetected in both direct detection experiments and searches at the LHC. In addition, in a sizable part of the parameter space, signals from more than one type of dark matter detection experiment would be possible, something that may eventually be necessary in order to identify the dark matter candidate.

  3. Complementarity of direct dark matter detection and indirect detection through gamma rays

    SciTech Connect (OSTI)

    Bergstroem, Lars; Bringmann, Torsten; Edsjoe, Joakim

    2011-02-15

    We show, by using an extensive sample of viable supersymmetric models as templates, that indirect detection of dark matter through gamma rays may have a large potential for identifying the nature of dark matter. This is, in particular, true also for models that give too weak dark matter-nucleon scattering cross sections to be probed by present and planned direct detection experiments. Also models with a mass scale too high to be accessible at CERN's LHC accelerator may show up in next-generation imaging Cherenkov telescope arrays. Based on our findings, we therefore suggest to view indirect searches as genuine particle physics experiments, complementing other strategies to probe so far unknown regions in the parameter space of e.g. supersymmetric models, and propose a new approach that would make use of telescopes dedicated for dark matter searches. As a concrete example for the potential of such an approach, we consider an array of imaging air Cherenkov telescopes, the Dark Matter Array (DMA), and show that such an experiment could extend present-day limits by several orders of magnitude, reaching a large class of models that would remain undetected in both direct detection experiments and searches at the LHC. In addition, in a sizable part of the parameter space, signals from more than one type of dark matter detection experiment would be possible, something that may eventually be necessary in order to identify the dark matter candidate.

  4. From the Dark Matter Universe to the Dark Energy Universe

    E-Print Network [OSTI]

    Burra G. Sidharth

    2008-03-30

    Till the late nineties the accepted cosmological model was that of a Universe that had originated in the Big Bang and was now decelerating under the influence of as yet undetected dark matter, so that it would come to a halt and eventually collapse. In 1997 however, the author had put forward a contra model wherein the Universe was driven by dark energy, essentially the quantum zero point field, and was accelerating with a small cosmological constant. There were other deductions too, all in total agreement with observation. All this got confirmation in 1998 and subsequent observations have reconfirmed the findings.

  5. Detectors for dark photon search with MESA

    SciTech Connect (OSTI)

    Molitor, Matthias [Johannes-Gutenberg University Mainz (Germany)

    2013-11-07

    The predictions of the standard model for the anomalous magnetic momentum of the muon, deviates from the direct measurements by 3,6 ?. A gauge boson of a new U(1)-Interaction, the so called dark photon, is predicted in many expansions of the standard model and could explain those deviations. In order to search for such a dark photon, a dedicated experiment is scheduled at the planned low energy accelerator MESA in Mainz. In order to detect dark photons this experiment needs a high resolution detector with a suitable acceptance.

  6. On the capture of dark matter by neutron stars

    SciTech Connect (OSTI)

    Güver, Tolga; Erkoca, Arif Emre; Sarcevic, Ina; Reno, Mary Hall E-mail: aeerkoca@gmail.com E-mail: ina@physics.arizona.edu

    2014-05-01

    We calculate the number of dark matter particles that a neutron star accumulates over its lifetime as it rotates around the center of a galaxy, when the dark matter particle is a self-interacting boson but does not self-annihilate. We take into account dark matter interactions with baryonic matter and the time evolution of the dark matter sphere as it collapses within the neutron star. We show that dark matter self-interactions play an important role in the rapid accumulation of dark matter in the core of the neutron star. We consider the possibility of determining an exclusion region of the parameter space for dark matter mass and dark matter interaction cross section with the nucleons as well as dark matter self-interaction cross section, based on the observation of old neutron stars. We show that for a dark matter density of 10{sup 3} GeV/cm{sup 3}and dark matter mass m{sub ?} ?< 10 GeV, there is a potential exclusion region for dark matter interactions with nucleons that is three orders of magnitude more stringent than without self-interactions. The potential exclusion region for dark matter self-interaction cross sections is many orders of magnitude stronger than the current Bullet Cluster limit. For example, for high dark matter density regions, we find that for m{sub ?} ? 10 GeV when the dark matter interaction cross section with the nucleons ranges from ?{sub ?n} ? 10{sup ?52} cm{sup 2} to ?{sub ?n} ? 10{sup ?57} cm{sup 2}, the dark matter self-interaction cross section limit is ?{sub ??} ?< 10{sup ?33} cm{sup 2}, which is about ten orders of magnitude stronger than the Bullet Cluster limit.

  7. Veto for the ZEPLIN-III dark matter detector 

    E-Print Network [OSTI]

    Barnes, Emma Jayne

    2010-01-01

    Cold dark matter in the form of weakly interacting massive particles (WIMPs) is a favoured explanation to the galactic dark matter puzzle and could account for a large proportion of the missing mass of the Universe. ...

  8. Lorentz-violating dark matter 

    E-Print Network [OSTI]

    Mondragon, Antonio Richard

    2009-05-15

    was originally motivated by an unconventional fundamental theory, but which in this dissertation is defined as matter which has a nonzero minimum velocity. Furthermore, the present investigation evolved into the broader goal of exploring the properties of Lorentz...

  9. Hunting for topological dark matter with atomic clocks

    E-Print Network [OSTI]

    A. Derevianko; M. Pospelov

    2014-12-08

    The cosmological applications of atomic clocks so far have been limited to searches of the uniform-in-time drift of fundamental constants. In this paper, we point out that a transient in time change of fundamental constants can be induced by dark matter objects that have large spatial extent, and are built from light non-Standard Model fields. The stability of this type of dark matter can be dictated by the topological reasons. We point out that correlated networks of atomic clocks, some of them already in existence, can be used as a powerful tool to search for the topological defect dark matter, thus providing another important fundamental physics application to the ever-improving accuracy of atomic clocks. During the encounter with a topological defect, as it sweeps through the network, initially synchronized clocks will become desynchronized. Time discrepancies between spatially-separated clocks are expected to exhibit a distinct signature, encoding defect's space structure and its interaction strength with the Standard Model fields.

  10. Effective Models for Dark Matter at the International Linear Collider

    E-Print Network [OSTI]

    Daniel Schmeier

    2013-08-20

    Weakly interacting massive particles (WIMPs) form a promising solution to the dark matter problem and many experiments are now searching for these particles. Using effective field theories to describe the interaction of the WIMP with the Standard Model has proven successful in providing an easy way to compare the different experimental results. In this work, we show how effective operators can be formally derived from a UV-complete underlying theory, and we analyse these operators in different experimental contexts. We put our main focus on the expected sensitivity of the International Linear Collider (ILC) in searching for WIMPs by looking at events with single photons in the final state. Furthermore, we show explicit evaluations of the relic density measurements from the Wilkinson Microwave Anisotropy Probe and the XENON Dark Matter Project direct detection measurements to compare to the expected ILC results. We find that the ILC serves as a unique tool to probe possible WIMP interactions with the Standard Model for dark matter masses below 10 GeV. This extends to masses up to 490 GeV in cases where the interaction is spin-dependent or leptophilic.

  11. Dark matter and structure formation a review

    E-Print Network [OSTI]

    Antonino Del Popolo

    2008-01-07

    This paper provides a review of the variants of dark matter which are thought to be fundamental components of the universe and their role in origin and evolution of structures and some new original results concerning improvements to the spherical collapse model. In particular, I show how the spherical collapse model is modified when we take into account dynamical friction and tidal torques.

  12. A Couplet from Flavored Dark Matter

    E-Print Network [OSTI]

    Prateek Agrawal; Zackaria Chacko; Can Kilic; Christopher B. Verhaaren

    2015-03-10

    We show that a couplet, a pair of closely spaced photon lines, in the X-ray spectrum is a distinctive feature of lepton flavored dark matter models for which the mass spectrum is dictated by Minimal Flavor Violation. In such a scenario, mass splittings between different dark matter flavors are determined by Standard Model Yukawa couplings and can naturally be small, allowing all three flavors to be long-lived and contribute to the observed abundance. Then, in the presence of a tiny source of flavor violation, heavier dark matter flavors can decay via a dipole transition on cosmological timescales, giving rise to three photon lines. The ratios of the line energies are completely determined in terms of the charged lepton masses, and constitute a firm prediction of this framework. For dark matter masses of order the weak scale, the couplet lies in the keV-MeV region, with a much weaker line in the eV-keV region. This scenario constitutes a potential explanation for the recent claim of the observation of a 3.5 keV line. The next generation of X-ray telescopes may have the necessary resolution to resolve the double line structure of such a couplet.

  13. A Couplet from Flavored Dark Matter

    E-Print Network [OSTI]

    Agrawal, Prateek; Kilic, Can; Verhaaren, Christopher B

    2015-01-01

    We show that a couplet, a pair of closely spaced photon lines, in the X-ray spectrum is a distinctive feature of lepton flavored dark matter models for which the mass spectrum is dictated by Minimal Flavor Violation. In such a scenario, mass splittings between different dark matter flavors are determined by Standard Model Yukawa couplings and can naturally be small, allowing all three flavors to be long-lived and contribute to the observed abundance. Then, in the presence of a tiny source of flavor violation, heavier dark matter flavors can decay via a dipole transition on cosmological timescales, giving rise to three photon lines. The ratios of the line energies are completely determined in terms of the charged lepton masses, and constitute a firm prediction of this framework. For dark matter masses of order the weak scale, the couplet lies in the keV-MeV region, with a much weaker line in the eV-keV region. This scenario constitutes a potential explanation for the recent claim of the observation of a 3.5 ke...

  14. Dark Matter Balls Help Supernovae to Explode

    E-Print Network [OSTI]

    Colin D. Froggatt; Holger B. Nielsen

    2015-03-03

    As a solution to the well-known problem that the shock wave potentially responsible for the explosion of a supernova actually tends to stall, we propose a new energy source arising from our model for dark matter. Our earlier model proposed that dark matter should consist of cm-large white dwarf-like objects kept together by a skin separating two different sorts of vacua. These dark matter balls or pearls will collect in the middle of any star throughout its lifetime. At some stage during the development of a supernova the balls will begin to take in neutrons and then other surrounding material. By passing into a ball nucleons fall through a potential of order 10 MeV, causing a severe production of heat - of order 10 foe for a solar mass of material eaten by the balls. The temperature in the iron core will thereby be raised, splitting up the iron into smaller nuclei. This provides a mechanism for reviving the shock wave when it arrives and making the supernova explosion really occur. The onset of the heating due to the dark matter balls would at first stop the collapse of the supernova progenitor. This opens up the possibility of there being {\\em two} collapses giving two neutrino outbursts, as apparently seen in the supernova SN1987A - one in Mont Blanc, and one 4 hours 43 minutes later in both IMB and Kamiokande.

  15. Mergers and Mass Assembly of Dark Matter Halos in a Lambda Cold Dark Matter Universe

    E-Print Network [OSTI]

    Fakhouri, Onsi Joe

    2010-01-01

    of a ? cold dark matter universe. MNRAS, 376:215–232, Marchlarge-scale structure in a universe dominated by cold darkfirst structures in the early Universe. Nature, 433:389–391,

  16. Could Dark Matter Interactions be an Alternative to Dark Energy ?

    E-Print Network [OSTI]

    S. Basilakos; M. Plionis

    2009-08-05

    We study the global dynamics of the universe within the framework of the Interacting Dark Matter (IDM) scenario. Assuming that the dark matter obeys the collisional Boltzmann equation, we can derive analytical solutions of the global density evolution, which can accommodate an accelerated expansion, equivalent to either the {\\em quintessence} or the standard $\\Lambda$ models, with the present time located after the inflection point. This is possible if there is a disequilibrium between the DM particle creation and annihilation processes with the former process dominating, which creates an effective source term with negative pressure. Comparing the predicted Hubble expansion of one of the IDM models (the simplest) with observational data we find that the effective annihilation term is quite small, as suggested by a variety of other recent experiments.

  17. Interacting Dark Matter as an Alternative to Dark Energy

    E-Print Network [OSTI]

    Spyros Basilakos; Manolis Plionis

    2009-11-12

    We investigate the global dynamics of the universe within the framework of the Interacting Dark Matter (IDM) scenario. Considering that the dark matter obeys the collisional Boltzmann equation, we can obtain analytical solutions of the global density evolution, which can accommodate an accelerated expansion, equivalent to either the {\\em quintessence} or the standard $\\Lambda$ models. This is possible if there is a disequilibrium between the DM particle creation and annihilation processes with the former process dominating, which creates an effective source term with negative pressure. Comparing the predicted Hubble expansion of one of the IDM models (the simplest) with observational data, we find that the effective annihilation term is quite small, as suggested by various experiments.

  18. Interacting Dark Matter as an Alternative to Dark Energy

    E-Print Network [OSTI]

    Basilakos, Spyros

    2009-01-01

    We investigate the global dynamics of the universe within the framework of the Interacting Dark Matter (IDM) scenario. Considering that the dark matter obeys the collisional Boltzmann equation, we can obtain analytical solutions of the global density evolution, which can accommodate an accelerated expansion, equivalent to either the {\\em quintessence} or the standard $\\Lambda$ models. This is possible if there is a disequilibrium between the DM particle creation and annihilation processes with the former process dominating, which creates an effective source term with negative pressure. Comparing the predicted Hubble expansion of one of the IDM models (the simplest) with observational data, we find that the effective annihilation term is quite small, as suggested by various experiments.

  19. Dynamics of substructures in warm dark-matter cosmologies

    E-Print Network [OSTI]

    Bastian Arnold; Alexander Knebe; Chris Power; Brad K. Gibson

    2008-11-13

    We performed cosmological simulations based upon both a cold dark matter (CDM) and a warm dark matter (WDM) model. The focus of our investigations lies with selected spatial and kinematic properties of substructure halos (subhalos) orbiting within host halos, that form in both dark-matter cosmologies. We aim at using the dynamics of the subhalos as a probe of the respective cosmology.

  20. The cosmic ray positron excess and neutralino dark matter

    E-Print Network [OSTI]

    Edward A. Baltz; Joakim Edsjo; Katherine Freese; Paolo Gondolo

    2001-12-14

    Using a new instrument, the HEAT collaboration has confirmed the excess of cosmic ray positrons that they first detected in 1994. We explore the possibility that this excess is due to the annihilation of neutralino dark matter in the galactic halo. We confirm that neutralino annihilation can produce enough positrons to make up the measured excess only if there is an additional enhancement to the signal. We quantify the `boost factor' that is required in the signal for various models in the Minimal Supersymmetric Standard Model parameter space, and study the dependence on various parameters. We find models with a boost factor greater than 30. Such an enhancement in the signal could arise if we live in a clumpy halo. We discuss what part of supersymmetric parameter space is favored (in that it gives the largest positron signal), and the consequences for other direct and indirect searches of supersymmetric dark matter.

  1. The Sensitivity of HAWC to High-Mass Dark Matter Annihilations

    E-Print Network [OSTI]

    A. U. Abeysekara; R. Alfaro; C. Alvarez; J. D. Alvarez; R. Arceo; J. C. Arteaga-Velazquez; H. A. Ayala Solares; A. S. Barber; B. M. Baughman; N. Bautista-Elivar; J. Becerra Gonzalez; E. Belmont; S. Y. BenZvi; D. Berley; M. Bonilla Rosales; J. Braun; R. A. Caballero-Lopez; K. S. Caballero-Mora; A. Carraminana; M. Castillo; U. Cotti; J. Cotzomi; E. de la Fuente; C. De Leon; T. DeYoung; R. Diaz Hernandez; L. Diaz-Cruz; J. C. Diaz-Velez; B. L. Dingus; M. A. DuVernois; R. W. Ellsworth; S. F. E.; D. W. Fiorino; N. Fraija; A. Galindo; F. Garfias; M. M. Gonzalez; J. A. Goodman; V. Grabski; M. Gussert; Z. Hampel-Arias; J. P. Harding; C. M. Hui; P. Huentemeyer; A. Imran; A. Iriarte; P. Karn; D. Kieda; G. J. Kunde; A. Lara; R. J. Lauer; W. H. Lee; D. Lennarz; H. Leon Vargas; E. C. Linares; J. T. Linnemann; M. Longo; R. Luna-Garcia; A. Marinelli; H. Martinez; O. Martinez; J. Martinez-Castro; J. A. J. Matthews; J. McEnery; E. Mendoza Torres; P. Miranda-Romagnoli; E. Moreno; M. Mostafa; L. Nellen; M. Newbold; R. Noriega-Papaqui; T. Oceguera-Becerra; B. Patricelli; R. Pelayo; E. G. Perez-Perez; J. Pretz; C. Riviere; D. Rosa-Gonzalez; J. Ryan; H. Salazar; F. Salesa; A. Sandoval; M. Schneider; S. Silich; G. Sinnis; A. J. Smith; K. Sparks Woodle; R. W. Springer; I. Taboada; P. A. Toale; K. Tollefson; I. Torres; T. N. Ukwatta; L. Villasenor; T. Weisgarber; S. Westerhoff; I. G. Wisher; J. Wood; G. B. Yodh; P. W. Younk; D. Zaborov; A. Zepeda; H. Zhou; K. N. Abazajian

    2014-12-09

    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained.

  2. Impact of the dark matter velocity distribution on capture rates in the Sun

    SciTech Connect (OSTI)

    Choi, K.; Itow, Y.; Rott, C. E-mail: rott@skku.edu

    2014-05-01

    Dark matter could be captured in the Sun and self-annihilate, giving rise to an observable neutrino flux. Indirect searches for dark matter looking for this signal with neutrino telescopes have resulted in tight constraints on the interaction cross-section of dark matter with ordinary matter. We investigate how robust limits are against astro-physical uncertainties. We study the effect of the velocity distribution of dark matter in our Galaxy on capture rates in the Sun. We investigate four sources of uncertainties: orbital speed of the Sun, escape velocity of dark matter from the halo, dark matter velocity distribution functions and existence of a dark disc. We find that even extreme cases currently discussed do not decrease the sensitivity of indirect detection significantly because the capture is achieved over a broad range of the velocity distribution by integration over the velocity distribution. The effect of the uncertainty in the high-velocity tail of dark matter halo is very marginal as the capture process is rather inefficient at this region. The difference in capture rate in the Sun for various scenarios is compared to the expected change in event rates for direct detection. The possibility of co-rotating structure with the Sun can largely boost the signal and hence makes the interpretation of indirect detection conservative compared to direct detection.

  3. A Large Scale Double Beta and Dark Matter Experiment: GENIUS

    E-Print Network [OSTI]

    J. Hellmig; H. V. Klapdor-Kleingrothaus

    1998-01-21

    The recent results from the HEIDELBERG-MOSCOW experiment have demonstrated the large potential of double beta decay to search for new physics beyond the Standard Model. To increase by a major step the present sensitivity for double beta decay and dark matter search much bigger source strengths and much lower backgrounds are needed than used in experiments under operation at present or under construction. We present here a study of a project proposed recently, which would operate one ton of 'naked' enriched GErmanium-detectors in liquid NItrogen as shielding in an Underground Setup (GENIUS). It improves the sensitivity to neutrino masses to 0.01 eV. A ten ton version would probe neutrino masses even down to 10^-3 eV. The first version would allow to test the atmospheric neutrino problem, the second at least part of the solar neutrino problem. Both versions would allow in addition significant contributions to testing several classes of GUT models. These are especially tests of R-parity breaking supersymmetry models, leptoquark masses and mechanism and right-handed W-boson masses comparable to LHC. The second issue of the experiment is the search for dark matter in the universe. The entire MSSM parameter space for prediction of neutralinos as dark matter particles could be covered already in a first step of the full experiment - with the same purity requirements but using only 100 kg of 76Ge or even of natural Ge - making the experiment competitive to LHC in the search for supersymmetry. The layout of the proposed experiment is discussed and the shielding and purity requirements are studied using GEANT Monte Carlo simulations. As a demonstration of the feasibility of the experiment first results of operating a 'naked' Ge detector in liquid nitrogen are presented.

  4. Diluted equilibrium sterile neutrino dark matter

    E-Print Network [OSTI]

    Amol V. Patwardhan; George M. Fuller; Chad T. Kishimoto; Alexander Kusenko

    2015-11-12

    We present a model where sterile neutrinos with rest masses in the range ~ keV to ~ MeV can be the dark matter and be consistent with all laboratory, cosmological, large-scale structure, as well as x-ray constraints. These sterile neutrinos are assumed to freeze out of thermal and chemical equilibrium with matter and radiation in the very early Universe, prior to an epoch of prodigious entropy generation ("dilution") from out-of-equilibrium decay of heavy particles. In this work, we consider heavy, entropy-producing particles in the ~ TeV to ~ EeV rest-mass range, possibly associated with new physics at high-energy scales. The process of dilution can give the sterile neutrinos the appropriate relic densities, but it also alters their energy spectra so that they could act like cold dark matter, despite relatively low rest masses as compared to conventional dark matter candidates. Moreover, since the model does not rely on active-sterile mixing for producing the relic density, the mixing angles can be small enough to evade current x-ray or lifetime constraints. Nevertheless, we discuss how future x-ray observations, future lepton number constraints, and future observations and sophisticated simulations of large-scale structure could, in conjunction, provide evidence for this model and/or constrain and probe its parameters.

  5. Diluted Equilibrium Sterile Neutrino Dark Matter

    E-Print Network [OSTI]

    Patwardhan, Amol V; Kishimoto, Chad T; Kusenko, Alexander

    2015-01-01

    We present a model where sterile neutrinos with rest masses in the range ~ keV to ~ MeV can be the dark matter and be consistent with all laboratory, cosmological, large scale structure, and X-ray constraints. These sterile neutrinos are assumed to freeze out of thermal and chemical equilibrium with matter and radiation in the very early universe, prior to an epoch of prodigious entropy generation ("dilution") from out-of-equilibrium decay of heavy particles. In this work, we consider heavy, entropy-producing particles in the ~ TeV to ~ EeV rest mass range, possibly associated with new physics at high energy scales. The process of dilution can give the sterile neutrinos the appropriate relic densities, but it also alters their energy spectra so that they could act like cold dark matter, despite relatively low rest masses as compared to conventional dark matter candidates. Moreover, since the model does not rely on active-sterile mixing for producing the relic density, the mixing angles can be small enough to ...

  6. An Alternative to Particle Dark Matter

    E-Print Network [OSTI]

    Justin Khoury

    2014-12-11

    We propose an alternative to particle dark matter that borrows ingredients of MOdified Newtonian Dynamics (MOND) while adding new key components. The first new feature is a dark matter fluid, in the form of a scalar field with small equation of state and sound speed. This component is critical in reproducing the success of cold dark matter for the expansion history and the growth of linear perturbations, but does not cluster significantly on non-linear scales. Instead, the missing mass problem on non-linear scales is addressed by a modification of the gravitational force law. The force law approximates MOND at large and intermediate accelerations, and therefore reproduces the empirical success of MOND at fitting galactic rotation curves. At ultra-low accelerations, the force law reverts to an inverse-square-law, albeit with a larger Newton's constant. This latter regime is important in galaxy clusters and is consistent with their observed isothermal profiles, provided the characteristic acceleration scale of MOND is mildly varying with scale or mass, such that it is ~12 times higher in clusters than in galaxies. We present an explicit relativistic theory in terms of two scalar fields. The first scalar field is governed by a Dirac-Born-Infeld action and behaves as a dark matter fluid on large scales. The second scalar field also has single-derivative interactions and mediates a fifth force that modifies gravity on non-linear scales. Both scalars are coupled to matter via an effective metric that depends locally on the fields. The form of this effective metric implies the equality of the two scalar gravitational potentials, which ensures that lensing and dynamical mass estimates agree. Further work is needed in order to make both the acceleration scale of MOND and the fraction at which gravity reverts to an inverse-square law explicitly dynamical quantities, varying with scale or mass.

  7. Discrimination of dark matter models in future experiments

    E-Print Network [OSTI]

    Tomohiro Abe; Ryuichiro Kitano; Ryosuke Sato

    2014-11-06

    Phenomenological aspects of simple dark matter models are studied. We discuss ways to discriminate the dark matter models in future experiments. We find that the measurements of the branching fraction of the Higgs boson into two photons and the electric dipole moment of the electron as well as the direct detection experiments are quite useful in discriminating particle models of dark matter. We also discuss the prospects of finding new particles in dark sector at the LHC/ILC.

  8. Dark-Matter-Induced Violation of the Weak Equivalence Principle

    SciTech Connect (OSTI)

    Carroll, Sean M.; Mantry, Sonny [California Institute of Technology, Pasadena, California 91125 (United States); Ramsey-Musolf, Michael J. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); California Institute of Technology, Pasadena, California 91125 (United States); Stubbs, Christoper W. [Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States)

    2009-07-03

    A long-range fifth force coupled to dark matter can induce a coupling to ordinary matter if the dark matter interacts with standard model fields. We consider constraints on such a scenario from both astrophysical observations and laboratory experiments. We also examine the case where the dark matter is a weakly interacting massive particle, and derive relations between the coupling to dark matter and the coupling to ordinary matter for different models. Currently, this scenario is most tightly constrained by galactic dynamics, but improvements in Eoetvoes experiments can probe unconstrained regions of parameter space.

  9. Dark matter interacts with variable vacuum energy

    E-Print Network [OSTI]

    Iván E. Sánchez G

    2014-09-21

    We investigate a spatially flat Friedmann-Robertson-Walker (FRW) scenario with two interacting components, dark matter and variable vacuum energy (VVE) densities, plus two decoupled components, one is a baryon term while the other behaves as a radiation component. We consider a linear interaction in the derivative dark component density. We apply the $\\chi^2$ method to the observational Hubble data for constraining the cosmological parameters and analyze the amount of dark energy in the radiation era for the model. It turns out that our model fulfills the severe bound of $\\Omega_{x}(z\\simeq 1100)energy at early times, and fulfills the stringent bound $\\Omega_{x}(z\\simeq 10^{10})today.

  10. Measurements of charge and light in pure high pressure Xe towards the study of Xe+TMA mixtures with dark matter directionality sensitivity and supra-intrinsic energy resolution for 0??? decay searches

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Oliveira, C. A.B.; Gehman, V.; Goldschmidt, A.; Nygren, D.; Renner, J.

    2015-03-24

    Trimethylamine (TMA) may improve the energy resolution of gaseous xenon based detectors for 0??? decay searches through the reduction of the Fano factor by the Penning effect. This molecule may also be the key for sensing directionality of nuclear recoils induced by Weakly Interacting Massive Particles (WIMPs) in monolithic massive (ton-scale) detectors, without the need of track imaging, by making use of columnar recombination. Nuclear recoil directionality may be the path for a definite discovery of the WIMP nature of Dark Matter. An ionization chamber has been constructed and operated to explore the properties of high pressure gaseous Xe +more »TMA mixtures for particle detection in rare-event experiments. The ionization, scintillation and electroluminescence (EL) signals are measured as function of pressure and electric field. We present results for pure xenon at pressures up to 8 bar. This work has been carried out within the context of the NEXT collaboration.« less

  11. Search for Dark Matter in Events with Missing Transverse Momentum and a Higgs Boson Decaying to Two Photons in pp Collisions at s?=8 TeV with the ATLAS Detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aad, G.

    2015-09-22

    Results of a search for new phenomena in events with large missing transverse momentum and a Higgs boson decaying to two photons are reported. Data from proton-proton collisions at a center-of-mass energy of 8 TeV and corresponding to an integrated luminosity of 20.3 fb-1 have been collected with the ATLAS detector at the LHC. The observed data are well described by the expected standard model backgrounds. Upper limits on the cross section of events with large missing transverse momentum and a Higgs boson candidate are also placed. Exclusion limits are presented for models of physics beyond the standard model featuringmore »dark-matter candidates.« less

  12. Holographic vortices in the presence of dark matter sector

    E-Print Network [OSTI]

    Marek Rogatko; Karol I. Wysokinski

    2015-10-21

    The {\\it dark matter} seem to be an inevitable ingredient of the total matter configuration in the Universe and the knowledge how the {\\it dark matter} affects the properties of superconductors is of vital importance for the experiments aimed at its direct detection. The homogeneous magnetic field acting perpendicularly to the surface of (2+1) dimensional s-wave holographic superconductor in the theory with {\\it dark matter} sector has been modeled by the additional $U(1)$-gauge field representing dark matter and coupled to the Maxwell one. As expected the free energy for the vortex configuration turns out to be negative. Importantly its value is lower in the presence of {\\it dark matter} sector. This feature can explain why in the Early Universe first the web of {\\it dark matter} appeared and next on these gratings the ordinary matter forming cluster of galaxies has formed.

  13. Inflaton dark matter from incomplete decay

    E-Print Network [OSTI]

    Mar Bastero-Gil; Rafael Cerezo; Joao G. Rosa

    2015-01-22

    We show that the decay of the inflaton field may be incomplete, while nevertheless successfully reheating the universe and leaving a stable remnant that accounts for the present dark matter abundance. We note, in particular, that since the mass of the inflaton decay products is field-dependent, one can construct models, endowed with an appropriate discrete symmetry, where inflaton decay is kinematically forbidden at late times and only occurs during the initial stages of field oscillations after inflation. We show that this is sufficient to ensure the transition to a radiation-dominated era and that inflaton particles typically thermalize in the process. They eventually decouple and freeze out, yielding a thermal dark matter relic. We discuss possible implementations of this generic mechanism within consistent cosmological and particle physics scenarios, for both single-field and hybrid inflation.

  14. Dark Matter Signals In Cosmic Rays?

    E-Print Network [OSTI]

    Shlomo Dado; Arnon Dar

    2009-03-10

    The flux of the diffuse gamma-ray background radiation (GBR) does not confirm that the excess in the flux of cosmic ray electrons between 300-800 GeV, which was measured locally with the ATIC instrument in balloon flights over Antartica, is universal as expected from dark matter annihilation. Neither does the increase with energy of the fraction of positrons in the cosmic ray flux of electrons in the 10-100 GeV range that was measured by PAMELA imply a dark matter origin: It is consistent with that expected from the sum of the two major sources of Galactic cosmic rays, non relativistic spherical ejecta and highly relativistic jets from supernova explosions.

  15. Dark Matter through the Axion Portal

    E-Print Network [OSTI]

    Yasunori Nomura; Jesse Thaler

    2008-11-07

    Motivated by the galactic positron excess seen by PAMELA and ATIC/PPB-BETS, we propose that dark matter is a TeV-scale particle that annihilates into a pseudoscalar "axion." The positron excess and the absence of an anti-proton or gamma ray excess constrain the axion mass and branching ratios. In the simplest realization, the axion is associated with a Peccei-Quinn symmetry, in which case it has a mass around 360-800 MeV and decays into muons. We present a simple and predictive supersymmetric model implementing this scenario, where both the Higgsino and dark matter obtain masses from the same source of TeV-scale spontaneous symmetry breaking.

  16. Directional detection of dark matter streams

    E-Print Network [OSTI]

    Ciaran A. J. O'Hare; Anne M. Green

    2014-11-11

    Directional detection of WIMPs, in which the energies and directions of the recoiling nuclei are measured, currently presents the only prospect for probing the local velocity distribution of Galactic dark matter. We investigate the extent to which future directional detectors would be capable of probing dark matter substructure in the form of streams. We analyse the signal expected from a Sagittarius-like stream and also explore the full parameter space of stream speed, direction, dispersion and density. Using a combination of non-parametric directional statistics, a profile likelihood ratio test and Bayesian parameter inference we find that within acceptable exposure times (O(10) kg yr for cross sections just below the current exclusion limits) future directional detectors will be sensitive to a wide range of stream velocities and densities. We also examine and discuss the importance of the energy window of the detector.

  17. First results from the DarkSide-50 dark matter experiment at Laboratori Nazionali del Gran Sasso

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Agnes, P.

    2015-03-11

    We report the first results of DarkSide-50, a direct search for dark matter operating in the underground Laboratori Nazionali del Gran Sasso (LNGS) and searching for the rare nuclear recoils possibly induced by weakly interacting massive particles (WIMPs). The dark matter detector is a Liquid Argon Time Projection Chamber with a (46.4 ± 0.7) kg active mass, operated inside a 30 t organic liquid scintillator neutron veto, which is in turn installed at the center of a 1 kt water Cherenkov veto for the residual flux of cosmic rays. We report here the null results of a dark matter searchmore »for a (1422 ± 67) kgd exposure with an atmospheric argon fill. This is the most sensitive dark matter search performed with an argon target, corresponding to a 90% CL upper limit on the WIMP-nucleon spin-independent cross section of 6.1×10??? cm² for a WIMP mass of 100 Gev/c² .« less

  18. Radio signals of particle dark matter

    E-Print Network [OSTI]

    Marco Regis

    2011-12-08

    In most of particle dark matter (DM) models, the DM candidate injects sizable fluxes of high-energy electrons and positrons through its annihilations or decays. Emitted in regions with magnetic field, they in turn give raise to a synchrotron radiation, which typically covers radio and infrared bands. We discuss the possibility of detecting signatures of Galactic and extra-galactic DM in the total intensity and small-scale anisotropies of the radio background.

  19. Dark matter and EWSB naturalness in unified SUSY models

    SciTech Connect (OSTI)

    Sandick, Pearl

    2013-05-23

    The relationship between the degree of fine-tuning in Electroweak Symmetry Breaking (EWSB) and the discoverability of dark matter in current and next generation direct detection experiments is investigated in the context of two unified Supersymmetry scenarios: the Constrained Minimal Supersymmetric Standard Model (CMSSM) and models with Non-Universal Higgs Masses (NUHM). Attention is drawn to the mechanism(s) by which the relic abundance of neutralino dark matter is suppressed to cosmologically viable values. After a summary of Amsel, Freese, and Sandick (2011), results are updated to reflect current constraints, including the discovery of a new particle consistent with a Standard Model-like Higgs boson. We find that a Higgs mass of {approx} 125 GeV excludes the least fine-tuned CMSSM points in our parameter space and that remaining viable models may be difficult to probe with next generation direct dark matter searches. Relatively low fine-tuning and good direct detection prospects are still possible in NUHM scenarios.

  20. Halo Formation in Warm Dark Matter Models

    E-Print Network [OSTI]

    Paul Bode; Jeremiah P. Ostriker; Neil Turok

    2001-05-29

    Discrepancies have emerged between the predictions of standard cold dark matter (CDM) theory and observations of clustering on sub-galactic scales. Warm dark matter (WDM) is a simple modification of CDM in which the dark matter particles have initial velocities due either to their having decoupled as thermal relics, or having been formed via non-equilibrium decay. We investigate the nonlinear gravitational clustering of WDM with a high resolution N-body code, and identify a number of distinctive observational signatures. Relative to CDM, halo concentrations and core densities are lowered, core radii are increased, and large halos emerge with far fewer low mass satellites. The number of small halos is suppressed, and those present are formed by `top down' fragmentation of caustics, as part of a `cosmic web' connecting massive halos. Few small halos form outside this web. If we identify small halos with dwarf galaxies, their number, spatial distribution, and formation epoch appear in better agreement with the observations for WDM than they are for CDM.

  1. Dark matter ignition of type Ia supernovae

    E-Print Network [OSTI]

    Bramante, Joseph

    2015-01-01

    Recent studies of low redshift type Ia supernovae (SNIa) indicate that half explode from less than Chandrasekhar mass white dwarfs, implying ignition must proceed from something besides the canonical criticality of Chandrasekhar mass SNIa progenitors. We show that $0.1-10$ PeV mass asymmetric dark matter, with imminently detectable nucleon scattering interactions, can accumulate to the point of self-gravitation in a white dwarf and collapse, shedding gravitational potential energy by scattering off nuclei, thereby heating the white dwarf and igniting the flame front that precedes SNIa. We combine data on SNIa masses with data on the ages of SNIa-adjacent stars. This combination reveals a $ 3 \\sigma$ inverse correlation between SNIa masses and ignition ages, which could result from increased capture of dark matter in 1.4 versus 1.1 solar mass white dwarfs. Future studies of SNIa in galactic centers will provide additional tests of dark-matter-induced type Ia ignition. Remarkably, both bosonic and fermionic SNI...

  2. Dark-matter harmonics beyond annual modulation

    SciTech Connect (OSTI)

    Lee, Samuel K.; Lisanti, Mariangela; Safdi, Benjamin R. E-mail: mlisanti@princeton.edu

    2013-11-01

    The count rate at dark-matter direct-detection experiments should modulate annually due to the motion of the Earth around the Sun. We show that higher-frequency modulations, including daily modulation, are also present and in some cases are nearly as strong as the annual modulation. These higher-order modes are particularly relevant if (i) the dark matter is light, O(10) GeV, (ii) the scattering is inelastic, or (iii) velocity substructure is present; for these cases, the higher-frequency modes are potentially observable at current and ton-scale detectors. We derive simple expressions for the harmonic modes as functions of the astrophysical and geophysical parameters describing the Earth's orbit, using an updated expression for the Earth's velocity that corrects a common error in the literature. For an isotropic halo velocity distribution, certain ratios of the modes are approximately constant as a function of nuclear recoil energy. Anisotropic distributions can also leave observable features in the harmonic spectrum. Consequently, the higher-order harmonic modes are a powerful tool for identifying a potential signal from interactions with the Galactic dark-matter halo.

  3. Dark matter cores all the way down

    E-Print Network [OSTI]

    Read, J I; Collins, M L M

    2015-01-01

    We use high resolution simulations of isolated dwarf galaxies to study the physics of dark matter cusp-core transformation at the edge of galaxy formation (Mvir = 10^7 - 10^9 Msun). We work at a resolution (4 pc) at which the impact from individual supernovae explosions can be resolved, becoming insensitive to even large changes in our numerical 'sub-grid' parameters. We find that our dwarf galaxies give a remarkable match to the stellar light profile; star formation history; metallicity distribution function; and star/gas kinematics of isolated dwarf irregular galaxies. Our key result is that dark matter cores of size comparable to the half light radius r_1/2 always form if star formation proceeds for long enough. Cores fully form in less than 4 Gyrs for the Mvir =10^8 Msun and 14 Gyrs for the 10^9 Msun dwarf. We provide a convenient two parameter 'coreNFW' fitting function that captures this dark matter core growth as a function of star formation time and the projected half light radius. Our results have se...

  4. Geometrical aspects on the dark matter problem

    SciTech Connect (OSTI)

    Capistrano, A.J.S.; Cabral, L.A.

    2014-09-15

    In the present paper we apply Nash’s theory of perturbative geometry to the study of dark matter gravity in a higher-dimensional space–time. It is shown that the dark matter gravitational perturbations at local scale can be explained by the extrinsic curvature of the standard cosmology. In order to test our model, we use a spherically symmetric metric embedded in a five-dimensional bulk. As a result, considering a sample of 10 low surface brightness and 6 high surface brightness galaxies, we find a very good agreement with the observed rotation curves of smooth hybrid alpha-HI measurements. - Highlights: • The metric perturbation and the embedding lead naturally to a “brane-world”-like higher dimensional structure. • Nash’s theorem as a cornerstone of the formation of geometrical structures. • The dark matter gravitational perturbations at local scale can be explained by the extrinsic curvature. • A good agreement was found with the observed rotation curves of smooth hybrid alpha-HI measurements.

  5. Vector Dark Matter through a Radiative Higgs Portal

    E-Print Network [OSTI]

    Anthony DiFranzo; Patrick J. Fox; Tim M. P. Tait

    2015-12-21

    We study a model of spin-1 dark matter which interacts with the Standard Model predominantly via exchange of Higgs bosons. We propose an alternative UV completion to the usual Vector Dark Matter Higgs Portal, in which vector-like fermions charged under SU(2)$_W \\times$ U(1)$_Y$ and under the dark gauge group, U(1)$^\\prime$, generate an effective interaction between the Higgs and the dark matter at one loop. We explore the resulting phenomenology and show that this dark matter candidate is a viable thermal relic and satisfies Higgs invisible width constraints as well as direct detection bounds.

  6. Fermilab | Science | Particle Physics | Dark matter and dark energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you not find whatGasEnergyfeature photo featureParticleDark matter and

  7. SQUID-based Resonant Detection of Axion Dark Matter

    E-Print Network [OSTI]

    Vladimir Popov

    2014-10-24

    A new method for searching for Dark Matter axions is proposed. It is shown that a two-contact SQUID can detect oscillating magnetic perturbations induced by the axions in a strong inhomogeneous magnetic field. A resonant signal is a steplike response in the SQUID current-voltage characteristic at a voltage corresponding to the axion mass with a height depending on the axion energy density near the Earth. The proposed experimental technique appears to be sensitive to the axions with masses $m_a\\lesssim 10^{-4}$ eV, which is well-motivated by current researches both in cosmology and in particle physics.

  8. Bi-metric Gravity and "Dark Matter"

    E-Print Network [OSTI]

    I. T. Drummond

    2000-08-18

    We present a bi-metric theory of gravity containing a length scale of galactic size. For distances less than this scale the theory satisfies the standard tests of General Relativity. For distances greater than this scale the theory yields an effective gravitational constant much larger than the locally observed value of Newton's constant. The transition from one regime to the other through the galactic scale can explain the observed rotation curves of galaxies and hence the effects normally attributed to the presence of dark matter. Phenomena on an extragalactic scale such as galactic clusters and the expansion of the universe are controlled by the enhanced gravitational coupling. This provides an explanation of the missing matter normally invoked to account for the observed value of Hubble's constant in relation to observed matter.

  9. Symplectic gauge fields and dark matter

    E-Print Network [OSTI]

    Asorey, J; Garcia-Alvarez, D

    2015-01-01

    The dynamics of symplectic gauge fields provides a consistent framework for fundamental interactions based on spin three gauge fields. One remarkable property is that symplectic gauge fields only have minimal couplings with gravitational fields and not with any other field of the Standard Model. Interactions with ordinary matter and radiation can only arise from radiative corrections. In spite of the gauge nature of symplectic fields they acquire a mass by the Coleman-Weinberg mechanism which generates Higgs-like mass terms where the gravitational field is playing the role of a Higgs field. Massive symplectic gauge fields weakly interacting with ordinary matter are natural candidates for the dark matter component of the Universe.

  10. Symplectic gauge fields and dark matter

    E-Print Network [OSTI]

    J. Asorey; M. Asorey; D. Garcia-Alvarez

    2015-11-02

    The dynamics of symplectic gauge fields provides a consistent framework for fundamental interactions based on spin three gauge fields. One remarkable property is that symplectic gauge fields only have minimal couplings with gravitational fields and not with any other field of the Standard Model. Interactions with ordinary matter and radiation can only arise from radiative corrections. In spite of the gauge nature of symplectic fields they acquire a mass by the Coleman-Weinberg mechanism which generates Higgs-like mass terms where the gravitational field is playing the role of a Higgs field. Massive symplectic gauge fields weakly interacting with ordinary matter are natural candidates for the dark matter component of the Universe.

  11. Manifestations of dark matter and variations of fundamental constants in atoms and astrophysical phenomena

    E-Print Network [OSTI]

    Y. V. Stadnik; V. V. Flambaum

    2015-09-03

    We present an overview of recent developments in the detection of light bosonic dark matter, including axion, pseudoscalar axion-like and scalar dark matter, which form either a coherently oscillating classical field or topological defects (solitons). We emphasise new high-precision laboratory and astrophysical measurements, in which the sought effects are linear in the underlying interaction strength between dark matter and ordinary matter, in contrast to traditional detection schemes for dark matter, where the effects are quadratic or higher order in the underlying interaction parameters and are extremely small. New terrestrial experiments include measurements with atomic clocks, spectroscopy, atomic and solid-state magnetometry, torsion pendula, ultracold neutrons, and laser interferometry. New astrophysical observations include pulsar timing, cosmic radiation lensing, Big Bang nucleosynthesis and cosmic microwave background measurements. We also discuss various recently proposed mechanisms for the induction of slow `drifts', oscillating variations and transient-in-time variations of the fundamental constants of Nature by dark matter, which offer a more natural means of producing a cosmological evolution of the fundamental constants compared with traditional dark energy-type theories, which invoke a (nearly) massless underlying field. Thus, measurements of variation of the fundamental constants gives us a new tool in dark matter searches.

  12. Constraining the Milky Way dark matter density profile with gamma-rays with Fermi-LAT

    SciTech Connect (OSTI)

    Bernal, Nicolás [Bethe Center for Theoretical Physics and Physikalisches Institut, Universität Bonn, Nußallee 12, D-53115 Bonn (Germany); Palomares-Ruiz, Sergio, E-mail: nicolas@th.physik.uni-bonn.de, E-mail: sergio.palomares.ruiz@ist.utl.pt [Centro de Física Teórica de Partículas (CFTP), Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2012-01-01

    We study the abilities of the Fermi-LAT instrument on board of the Fermi mission to simultaneously constrain the Milky Way dark matter density profile and some dark matter particle properties, as annihilation cross section, mass and branching ratio into dominant annihilation channels. A single dark matter density profile is commonly assumed to determine the capabilities of gamma-ray experiments to extract dark matter properties or to set limits on them. However, our knowledge of the Milky Way halo is far from perfect, and thus in general, the obtained results are too optimistic. Here, we study the effect these astrophysical uncertainties would have on the determination of dark matter particle properties and conversely, we show how gamma-ray searches could also be used to learn about the structure of the Milky Way halo, as a complementary tool to other type of observational data that study the gravitational effect caused by the presence of dark matter. In addition, we also show how these results would improve if external information on the annihilation cross section and on the local dark matter density were included and compare our results with the predictions from numerical simulations.

  13. Cosmic inflation, deceleration, acceleration, dark matter, and dark `energy' in one coherent package

    E-Print Network [OSTI]

    Ellis, Homer

    Cosmic inflation, deceleration, acceleration, dark matter, and dark `energy' in one coherent to (mis)represent a uniform negative net mass density of gravitationally attractive and gravitationally, baryonic particles of primordial matter and as the continuously created, invisible particles of the `dark

  14. Why we need to see the dark matter to understand the dark energy

    E-Print Network [OSTI]

    Martin Kunz

    2007-10-30

    The cosmological concordance model contains two separate constituents which interact only gravitationally with themselves and everything else, the dark matter and the dark energy. In the standard dark energy models, the dark matter makes up some 20% of the total energy budget today, while the dark energy is responsible for about 75%. Here we show that these numbers are only robust for specific dark energy models and that in general we cannot measure the abundance of the dark constituents separately without making strong assumptions.

  15. Higgs portal vector dark matter for GeV scale ?-ray excess from galactic center

    SciTech Connect (OSTI)

    Ko, P.; Park, Wan-Il; Tang, Yong E-mail: wipark@kias.re.kr

    2014-09-01

    We show that the GeV scale ?-ray excess from the direction of the Galactic Center can be naturally explained by the pair annihilation of Abelian vector dark matter (VDM) into a pair of dark Higgs bosons (VV? ? ?), followed by the subsequent decay of ? into b b-bar or ? ?-bar  . All the processes are described by a renormalizable VDM model with the Higgs portal, which is naturally flavor-dependent. Some parameter space of this scenario can be tested at the near future direct dark matter search experiments such as LUX and XENON1T.

  16. Dark Energy and Search for the Generalized Second Law

    E-Print Network [OSTI]

    Balendra Kr. Dev Choudhury; Julie Saikia

    2009-06-03

    The discovery of accelerated Hubble expansion in the SNIa data and the observed power spectrum of the microwave background radiation provide an ample support for Dark energy and Dark matter. Except for the so far well-known facts that cold dark matter (or simply dark matter) is pressureless, and dark energy has a negative pressure, the nature of these two still remains a complete mystery. The mystery facilitates different consideration. In one hand, dark matter and dark energy are assumed as distinct entities, and other interpretation is that both are different manifestation of a common structure, often referred as quartessence. Chaplygin gas, a perfect fluid also favours the second interpretation. Here, we consider modified chaplygin gas as dark energy candidate. Taking into account the existence of the observer's event horizon in accelerated universe, we find the condition where the generalized second law of gravitational thermodynamics is valid and the positivity of the temperature of the phantom fluid remains intact.

  17. Evidence for dark matter interactions in cosmological precision data?

    E-Print Network [OSTI]

    Julien Lesgourgues; Gustavo Marques-Tavares; Martin Schmaltz

    2015-09-09

    We study a two-parameter extension of the cosmological standard model $\\Lambda$CDM in which cold dark matter interacts with a new form of dark radiation. The two parameters correspond to the energy density in the dark radiation $\\Delta N_\\mathrm{eff}$ and the interaction strength between the dark matter and dark radiation fluids. The interactions give rise to a very weak "dark matter drag" which damps the growth of matter density perturbations throughout radiation domination, allowing to reconcile the tension between predictions of large scale structure from the CMB and direct measurements of $\\sigma_8$. We perform a precision fit to Planck CMB data, BAO, large scale structure, and direct measurements of the expansion rate of the universe today. Our model lowers the $\\chi$-squared relative to $\\Lambda$CDM by about 11, corresponding to a preference for non-zero dark matter drag by more than $3 \\sigma$. Particle physics models which naturally produce a dark matter drag of the required form include the recently proposed non-Abelian dark matter model in which the dark radiation corresponds to massless dark gluons.

  18. From dark matter to neutrinoless double beta decay

    E-Print Network [OSTI]

    Pei-Hong Gu

    2012-09-13

    Associated with two TeV-scale leptoquark scalars, a dark matter fermion which is the neutral component of an isotriplet can mediate a testable neutrinoless double beta decay at one-loop level. The dark matter fermion with determined mass and spin-independent scattering can be verified by the future dark matter direct detection experiments. We also discuss the implications on neutrino masses and baryon asymmetry.

  19. Results from the XENON10 and the Race to Detect Dark Matter with Noble Liquids

    ScienceCinema (OSTI)

    Shutt, Tom [Case Western Reserve, Cleveland, Ohio, United States

    2009-09-01

    Detectors based on liquid noble gases have the potential to revolutionize the direct search for WIMP dark matter. The XENON10 experiment, of which I am a member, has recently announced the results from it's first data run and is now the leading WIMP search experiment. This and other experiments using xenon, argon and neon have the potential to rapidly move from the current kg-scale target mass to the ton scale and well beyond. This should allow a (nearly) definitive test or discovery of dark matter if it is in the form of weakly interacting massive particles.

  20. Neutrinoless double beta decay can constrain neutrino dark matter

    E-Print Network [OSTI]

    V. Barger; S. L. Glashow; D. Marfatia; K. Whisnant

    2002-02-26

    We examine how constraints can be placed on the neutrino component of dark matter by an accurate measurement of neutrinoless double beta ($0\

  1. Higgs portal dark matter at a linear collider

    E-Print Network [OSTI]

    Takehiro Nabeshima

    2012-02-23

    We investigate the possibility of detecting dark matter at TeV scale linear colliders in the scenario where the dark matter interacts with standard model particles only via the Higgs boson. In this scenario, the dark matter would be difficult to be tested at the LHC especially when the decay of the Higgs boson into a dark matter pair is not kinematically allowed. In this talk, we discuss whether even such a case can be explored or not at the ILC and CLIC via the Z boson fusion process. This talk is mainly based on Phys. Rev. D 82, 055026 (2010) and Phys. Lett. B 701, 591 (2011).

  2. Next Generation of Direct Detection Dark Matter Experiments Announced...

    Office of Science (SC) Website

    Detection Dark Matter Experiments Announced High Energy Physics (HEP) HEP Home About Research Facilities Science Highlights Benefits of HEP Funding Opportunities Advisory...

  3. Making the Dark Matter Connection Between Particle Physics and Cosmology 

    E-Print Network [OSTI]

    Krislock, Abram Michael

    2012-10-19

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Figure 3 Dark Matter Relic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 4 Jet- - Decay Chain... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 5 W -plus-Jet Decay Chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 6 Ditau Invariant Mass...

  4. Isospin-Violating Dark Matter in the Sun

    E-Print Network [OSTI]

    Yu Gao; Jason Kumar; Danny Marfatia

    2011-09-27

    We consider the prospects for studying spin-independent isospin-violating dark matter-nucleon interactions with neutrinos from dark matter annihilation in the Sun, with a focus on IceCube/DeepCore (IC/DC). If dark matter-nucleon interactions are isospin violating, IC/DC's reach in the spin-independent cross section may be competitive with current direct detection experiments for a wide range of dark matter masses. We also compare IC/DC's sensitivity to that of next generation argon, germanium, neon and xenon based detectors.

  5. The effect of early dark matter halos on reionization

    E-Print Network [OSTI]

    Aravind Natarajan; Dominik J. Schwarz

    2008-11-21

    The annihilation of dark matter particles releases energy, ionizing some of the gas in the Universe. We investigate the effect of dark matter halos on reionization. We show that the effect depends on the assumed density profile, the particle mass, and the assumed minimum halo mass. For NFW halos and typical WIMPs, we find the effect to be quite small. However, light dark matter candidates in the MeV range can contribute significantly to reionization and can make an important contribution to the measured optical depth. This effect may be used to constrain light dark matter models. We also study the effect of varying the halo density profile on reionization.

  6. Constraints on Light Dark Matter from Big Bang Nucleosynthesis

    E-Print Network [OSTI]

    Brian Henning; Hitoshi Murayama

    2012-05-29

    We examine the effects of relic dark matter annihilations on big bang nucleosynthesis (BBN). The magnitude of these effects have scale simply with the dark matter mass and annihilation cross-section, which we derive. Estimates based on these scaling behaviors indicate that BBN severely constrains hadronic and radiative dark matter annihilation channels in the previously unconsidered dark matter mass region MeV $\\lesssim m_{\\chi} \\lesssim 10$ GeV. Interestingly, we find that BBN constraints on hadronic annihilation channels are competitive with similar bounds derived from the cosmic microwave background.

  7. Towards graphene-based detectors for dark matter directional detection

    E-Print Network [OSTI]

    Wang, Shang-Yung

    2015-01-01

    Dark matter detectors with directional sensitivity have the capability to distinguish dark matter induced nuclear recoils from isotropic backgrounds, thus providing a smoking gun signature for dark matter in the Galactic halo. Here we propose a conceptually novel class of high directional sensitivity dark matter detectors utilizing graphene-based van der Waals heterostructures. The advantages over conventional low pressure gas time projection chamber-based directional detectors are discussed in detail. A practical implementation using graphene/hexagonal boron nitride and graphene/molybdenum disulfide heterostructures is presented together with an overwhelming amount of experimental evidence in strong support of its feasibility.

  8. Direct Detection of sub-GeV Dark Matter with Semiconductor Targets

    E-Print Network [OSTI]

    Rouven Essig; Marivi Fernandez-Serra; Jeremy Mardon; Adrian Soto; Tomer Volansky; Tien-Tien Yu

    2015-09-04

    Dark matter in the sub-GeV mass range is a theoretically motivated but largely unexplored paradigm. Such light masses are out of reach for conventional nuclear recoil direct detection experiments, but may be detected through the small ionization signals caused by dark matter-electron scattering. Semiconductors are well-studied and are particularly promising target materials because their ${\\cal O}(1~\\rm{eV})$ band gaps allow for ionization signals from dark matter as light as a few hundred keV. Current direct detection technologies are being adapted for dark matter-electron scattering. In this paper, we provide the theoretical calculations for dark matter-electron scattering rate in semiconductors, overcoming several complications that stem from the many-body nature of the problem. We use density functional theory to numerically calculate the rates for dark matter-electron scattering in silicon and germanium, and estimate the sensitivity for upcoming experiments such as DAMIC and SuperCDMS. We find that the reach for these upcoming experiments has the potential to be orders of magnitude beyond current direct detection constraints and that sub-GeV dark matter has a sizable modulation signal. We also give the first direct detection limits on sub-GeV dark matter from its scattering off electrons in a semiconductor target (silicon) based on published results from DAMIC. We make available publicly our code, QEdark, with which we calculate our results. Our results can be used by experimental collaborations to calculate their own sensitivities based on their specific setup. The searches we propose will probe vast new regions of unexplored dark matter model and parameter space.

  9. Dark Matter Directionality Revisited with a High Pressure Xenon Gas Detector

    E-Print Network [OSTI]

    Gopolang Mohlabeng; Kyoungchul Kong; Jin Li; Adam Para; Jonghee Yoo

    2015-11-19

    An observation of the anisotropy of dark matter interactions in a direction-sensitive detector would provide decisive evidence for the discovery of galactic dark matter. Directional information would also provide a crucial input to understanding its distribution in the local Universe. Most of the existing directional dark matter detectors utilize particle tracking methods in a low-pressure gas time projection chamber. These low pressure detectors require excessively large volumes in order to be competitive in the search for physics beyond the current limit. In order to avoid these volume limitations, we consider a novel proposal, which exploits a columnar recombination effect in a high-pressure gas time projection chamber. The ratio of scintillation to ionization signals observed in the detector carries the angular information of the particle interactions. In this paper, we investigate the sensitivity of a future directional detector focused on the proposed high-pressure Xenon gas time projection chamber. We study the prospect of detecting an anisotropy in the dark matter velocity distribution. We find that tens of events are needed to exclude an isotropic distribution of dark matter interactions at 95% confidence level in the most optimistic case with head-to-tail information. However, one needs at least 10-20 times more events without head-to-tail information for light dark matter below 50 GeV. For an intermediate mass range, we find it challenging to observe an anisotropy of the dark matter distribution. Our results also show that the directional information significantly improves precision measurements of dark matter mass and the elastic scattering cross section for a heavy dark matter.

  10. Dark matter directionality revisited with a high pressure xenon gas detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mohlabeng, Gopolang; Kong, Kyoungchul; Li, Jin; Para, Adam; Yoo, Jonghee

    2015-07-20

    An observation of the anisotropy of dark matter interactions in a direction-sensitive detector would provide decisive evidence for the discovery of galactic dark matter. Directional information would also provide a crucial input to understanding its distribution in the local Universe. Most of the existing directional dark matter detectors utilize particle tracking methods in a low-pressure gas time projection chamber. These low pressure detectors require excessively large volumes in order to be competitive in the search for physics beyond the current limit. In order to avoid these volume limitations, we consider a novel proposal, which exploits a columnar recombination effect inmore »a high-pressure gas time projection chamber. The ratio of scintillation to ionization signals observed in the detector carries the angular information of the particle interactions. In this paper, we investigate the sensitivity of a future directional detector focused on the proposed high-pressure Xenon gas time projection chamber. We study the prospect of detecting an anisotropy in the dark matter velocity distribution. We find that tens of events are needed to exclude an isotropic distribution of dark matter interactions at 95% confidence level in the most optimistic case with head-to-tail information. However, one needs at least 10-20 times more events without head-to-tail information for light dark matter below ~50 GeV. For an intermediate mass range, we find it challenging to observe an anisotropy of the dark matter distribution. Our results also show that the directional information significantly improves precision measurements of dark matter mass and the elastic scattering cross section for a heavy dark matter.« less

  11. Sensitivity of CTA to dark matter signals from the Galactic Center

    E-Print Network [OSTI]

    Mathias Pierre; Jennifer M. Siegal-Gaskins; Pat Scott

    2014-10-13

    (abridged) The Galactic Center is one of the most promising targets for indirect detection of dark matter with gamma rays. We investigate the sensitivity of the upcoming Cherenkov Telescope Array (CTA) to dark matter annihilation and decay in the Galactic Center. As the inner density profile of the Milky Way's dark matter halo is uncertain, we study the impact of the slope of the Galactic density profile, inwards of the Sun, on the prospects for detecting a dark matter signal with CTA. We find that the sensitivity achieved by CTA to annihilation signals is strongly dependent on the inner profile slope, whereas the dependence is more mild in the case of dark matter decay. Surprisingly, we find that the optimal choice of signal and background regions is virtually independent of the assumed density profile. For the fiducial case of a Navarro-Frenk-White profile, we find that CTA will be able to probe annihilation cross sections well below the canonical thermal relic value for dark matter masses from a few tens of GeV up to $\\sim 5$ TeV for annihilation to $\\tau^{+}\\tau^{-}$, and will achieve only a slightly weaker sensitivity for annihilation to $b\\bar{b}$ or $\\mu^{+}\\mu^{-}$. CTA will improve significantly on current sensitivity to annihilation signals for dark matter masses above $\\sim 100$ GeV, covering parameter space that is complementary to that probed by searches with the Fermi Large Area Telescope. The interpretation of apparent excesses in the measured cosmic-ray electron and positron spectra as signals of dark matter decay will also be testable with CTA observations of the Galactic Center. We demonstrate that both for annihilation and for decay, including spectral information for hard channels (such as $\\mu^{+}\\mu^{-}$ and $\\tau^{+}\\tau^{-}$) leads to enhanced sensitivity for dark matter masses above $m_{\\rm DM}\\sim 200$ GeV.

  12. Splashback in accreting dark matter halos

    SciTech Connect (OSTI)

    Adhikari, Susmita; Dalal, Neal; Chamberlain, Robert T. E-mail: dalaln@illinois.edu

    2014-11-01

    Recent work has shown that density profiles in the outskirts of dark matter halos can become extremely steep over a narrow range of radius. This behavior is produced by splashback material on its first apocentric passage after accretion. We show that the location of this splashback feature may be understood quite simply, from first principles. We present a simple model, based on spherical collapse, that accurately predicts the location of splashback without any free parameters. The important quantities that determine the splashback radius are accretion rate and redshift.

  13. Photonic dark matter portal and quantum physics

    E-Print Network [OSTI]

    S. A. Alavi; F. S. Kazemian

    2015-06-14

    We study a model of dark matter in which the hidden sector interacts with standard model particles via a hidden photonic portal. We investigate the effects of this new interaction on the hydrogen atom, including the Stark, Zeeman and hyperfine effects. Using the accuracy of the measurement of energy, we obtain an upper bound for the coupling constant of the model. We also calculate the contribution from the hidden photonic portal to the anomalous magnetic moment of the muon, which provides an important probe of physics beyond the standard model.

  14. Cosmic antiprotons as a probe for neutralino dark matter?

    E-Print Network [OSTI]

    Lars Bergstrom; Joakim Edsjo; Piero Ullio

    1999-06-02

    The flux of cosmic ray antiprotons from neutralino annihilations in the galactic halo is computed for a large sample of models in the Minimal Supersymmetric extension of the Standard Model. We also revisit the problem of estimating the background of low-energy cosmic ray induced secondary antiprotons, taking into account their subsequent interactions (and energy loss) and the presence of nuclei in the interstellar matter. We point out that in some cases the optimal kinetic energy to search for a signal from supersymmetric dark matter is above several GeV, rather than the traditional sub-GeV region. The large astrophysical uncertainties involved do not allow the exclusion of any of the MSSM models we consider, on the basis of current data.

  15. Multi-Higgs portal dark matter under the CDMS II results

    E-Print Network [OSTI]

    Mayumi Aoki; Shinya Kanemura; Osamu Seto

    2010-02-08

    In a scenario of Higgs portal dark matter, Higgs exchange processes are essential for both dark matter annihilation in the early Universe and direct search experiments. The CDMS II collaboration has recently released their final results on direct dark matter searches. We study a scalar dark matter model with multi-Higgs doublets under the constraint from the CDMS II results and also from the WMAP data. We find that the possible maximal value for the branching ratio of the invisible decay of the Higgs boson can be significantly greater than that in the Higgs portal model with one Higgs doublet, in particular, for the case of the so-called Type-X Yukawa interaction. Therefore, the search for the invisible decay of the Higgs boson at the CERN Large Hadron Collider and future collider experiments would provide useful information not only for the nature of dark matter but also for the structure of the Higgs sector even without directly detecting any extra scalar boson.

  16. Fermion dark matter from SO(10)

    E-Print Network [OSTI]

    Carolina Arbelaez; Robinson Longas; Diego Restrepo; Oscar Zapata

    2015-09-21

    We construct and analyze non-supersymmetric SO(10) standard model extensions which explain dark matter (DM) through the fermionic Higgs portal. In these SO(10)-based models the DM particle is naturally stable since a $Z_2$ discrete symmetry, the matter parity, is left at the end of the symmetry breaking chain to the standard model. Potentially realistic models contain the $\\bf{10}$ and $\\bf{45}$ fermionic representations from which a neutralino-like mass matrix with arbitrary mixings can be obtained. Two different SO(10) breaking chains will be analyzed in light of gauge coupling unification: the standard path $\\text{SU}(5)\\times U(1)_{X}$ and the left-right symmetry intermediate chain. The former opens the possibility of a split supersymmetric-like spectrum with an additional (inert) scalar doublet, while the later requires additional exotic scalar representations associated to the breaking of the left-right symmetry.

  17. The Higgs portal and an unified model for dark energy and dark matter

    E-Print Network [OSTI]

    O. Bertolami; R. Rosenfeld

    2007-08-22

    We examine a scenario where the Higgs boson is coupled to an additional singlet scalar field which we identify with a quintessence field. We show that this results in an unified picture of dark matter and dark energy, where dark energy is the zero-mode classical field rolling the usual quintessence potential and the dark matter candidate is the quantum excitation (particle) of the field, which is produced in the universe due to its coupling to the Higgs boson.

  18. Search for a Dark Photon ine+e-Collisions atBaBar

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lees, J.?P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D.?N.; Feng, M.; Kerth, L.?T.; et al

    2014-11-10

    Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A'), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e+e-??A', A'?e+e-, ?+?- using 514 fb-1 of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of10-4-10-3 for dark photonmore »masses in the range 0.02–10.2 GeV We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon.« less

  19. A fluid mechanical explanation of dark matter

    E-Print Network [OSTI]

    Carl H. Gibson

    1999-04-22

    Matter in the universe has become ``dark'' or ``missing'' through misconceptions about the fluid mechanics of gravitational structure formation. Gravitational condensation occurs on non-acoustic density nuclei at the largest Schwarz length scale L_{ST}, L_{SV}, L_{SM}, L_{SD} permitted by turbulence, viscous, or magnetic forces, or by the fluid diffusivity. Non-baryonic fluids have diffusivities larger (by factors of trillions or more) than baryonic (ordinary) fluids, and cannot condense to nucleate baryonic galaxy formation as is usually assumed. Baryonic fluids begin to condense in the plasma epoch at about 13,000 years after the big bang to form proto-superclusters, and form proto-galaxies by 300,000 years when the cooling plasma becomes neutral gas. Condensation occurs at small planetary masses to form ``primordial fog particles'' from nearly all of the primordial gas by the new theory, Gibson (1996), supporting the Schild (1996) conclusion from quasar Q0957+651A,B microlensing observations that the mass of the lens galaxy is dominated by ``rogue planets ... likely to be the missing mass''. Non-baryonic dark matter condenses on superclusters at scale L_{SD} to form massive super-halos.

  20. Spin Dependence of Dark Matter Scattering

    E-Print Network [OSTI]

    Vernon Barger; Wai-Yee Keung; Gabe Shaughnessy

    2008-06-11

    New experiments designed to discover a weakly interacting dark matter (DM) particle via spin dependent scattering can distinguish models of electroweak symmetry breaking. The plane of spin dependent versus spin independent DM scattering cross sections is a powerful model diagnostic. We detail representative predictions of mSUGRA, singlet extended SM and MSSM, a new Dirac neutrino, Littlest Higgs with T-parity (LHT) and Minimal Universal Extra Dimensions (mUED) models. Of these models, the nMSSM has the largest spin dependent (SD) cross section. It has a very light neutralino which would give lower energy nuclear recoils. The Focus Point region of mSUGRA, mUED and the right handed neutrino also predict a very large SD cross section and predict a large signal of high energy neutrinos in the IceCube experiment from annihilations of dark matter in the Sun. We also describe a model independent treatment of the scattering of DM particles of different intrinsic spins.

  1. Observational consequencies of baryonic gaseous dark matter

    E-Print Network [OSTI]

    Shchekinov, Yu A

    1998-01-01

    Possible observational consequencies of dark matter in the Galaxy in the form of dense molecular gas clouds -- clumpuscules of masses $M_c\\sim 10^{-3}~\\msun$ and radii $R_c\\sim 3\\times 10^{13}$ cm -- are considered. Recent models of the extreme scattering events -- refraction of radio-waves from quasars in dense plasma clumps in the Galactic halo -- definitely show on such clouds as possible dark matter candidate. We arugue that collisions of such clumpuscules are quite frequent: around $1-10~\\msun$ a year can be ejected in the intestellar medium due to collisions. Optical continuum and 21 cm emissions from post-collisional gas are found to be observable. We show that clumpuscules can form around O stars HII regions of sizes $R\\sim 30$ pc and emission measure $EM\\simeq 20$ cm$^{-6}$ pc, and can also be observable in $H_\\alpha$ emission. Evaporation of clumpuscules by external ionising radiation can be a substantial mass source. From requirement that the total mass input on the Hubble time cannot exceed the lu...

  2. Observational consequences of baryonic gaseous dark matter

    E-Print Network [OSTI]

    Yu. A. Shchekinov

    1998-12-03

    Possible observational consequences of dark matter in the Galaxy in the form of dense molecular gas clouds - clumpuscules of masses $M_c\\sim 10^{-3} \\msun$ and radii $R_c\\sim 3\\times 10^{13}$ cm - are considered. Recent models of the extreme scattering events - refraction of radio-waves from quasars in dense plasma clumps in the Galactic halo - definitely show on such clouds as possible dark matter candidate. We argue that collisions of such clumpuscules are quite frequent: around $1-10 \\msun$ a year can be ejected in the interstellar medium due to collisions. Optical continuum and 21 cm emissions from post-collisional gas are found to be observable. We show that clumpuscules can form around O stars HII regions of sizes $R\\sim 30$ pc and emission measure $EM\\simeq 20 cm^{-6}$ pc, and can also be observable in $H_\\alpha$ emission. Evaporation of clumpuscules by external ionizing radiation can be a substantial mass source. From requirement that the total mass input on the Hubble time cannot exceed the luminous mass in the Galaxy, typical radius of clouds is constrained as $R_c energy of the gas ejected by such clouds can be an efficient energy source for the Galactic halo.

  3. Dark matter and neutrino masses from a scale-invariant multi-Higgs portal

    E-Print Network [OSTI]

    Alexandros Karam; Kyriakos Tamvakis

    2015-09-05

    We consider a classically scale invariant version of the Standard Model, extended by an extra dark $SU(2)_X$ gauge group. Apart from the dark gauge bosons and a dark scalar doublet which is coupled to the Standard Model Higgs through a portal coupling, we incorporate right-handed neutrinos and an additional real singlet scalar field. After symmetry breaking \\`a la Coleman-Weinberg, we examine the multi-Higgs sector and impose theoretical and experimental constraints. In addition, by computing the dark matter relic abundance and the spin-independent scattering cross section off a nucleon we determine the viable dark matter mass range in accordance with present limits. The model can be tested in the near future by collider experiments and direct detection searches such as XENON 1T.

  4. Dark matter and neutrino masses from a scale-invariant multi-Higgs portal

    E-Print Network [OSTI]

    Karam, Alexandros

    2015-01-01

    We consider a classically scale invariant version of the Standard Model, extended by an extra dark $SU(2)_X$ gauge group. Apart from the dark gauge bosons and a dark scalar doublet which is coupled to the Standard Model Higgs through a portal coupling, we incorporate right-handed neutrinos and an additional real singlet scalar field. After symmetry breaking \\`{a} la Coleman-Weinberg, we examine the multi-Higgs sector and impose theoretical and experimental constraints. In addition, by computing the dark matter relic abundance and the spin-independent scattering cross section off a nucleon we determine the viable dark matter mass range in accordance with present limits. The model can be tested in the near future by collider experiments and direct detection searches such as XENON 1T.

  5. A Terrestrial Search for Dark Contents of the Vacuum, Such as Dark Energy, Using Atom Interferometry

    SciTech Connect (OSTI)

    Adler, Ronald J.; Muller, Holger; Perl, Martin L.; /KIPAC, Menlo Park /SLAC

    2012-06-11

    We describe the theory and first experimental work on our concept for searching on earth for the presence of dark contents of the vacuum (DCV) using atom interferometry. Specifically, we have in mind any DCV that has not yet been detected on a laboratory scale, but which might manifest itself as dark energy on the cosmological scale. The experimental method uses two atom interferometers to cancel the effect of earth's gravity and diverse noise sources. It depends upon two assumptions: first, that the DCV possesses some space inhomogeneity in density, and second that it exerts a sufficiently strong nongravitational force on matter. The motion of the apparatus through the DCV should then lead to an irregular variation in the detected matter-wave phase shift. We discuss the nature of this signal and note the problem of distinguishing it from instrumental noise. We also discuss the relation of our experiment to what might be learned by studying the noise in gravitational wave detectors such as LIGO. The paper concludes with a projection that a future search of this nature might be carried out using an atom interferometer in an orbiting satellite. The laboratory apparatus is now being constructed.

  6. Warm and cold fermionic dark matter via freeze-in

    SciTech Connect (OSTI)

    Klasen, Michael; Yaguna, Carlos E. E-mail: carlos.yaguna@uni-muenster.de

    2013-11-01

    The freeze-in mechanism of dark matter production provides a simple and intriguing alternative to the WIMP paradigm. In this paper, we analyze whether freeze-in can be used to account for the dark matter in the so-called singlet fermionic model. In it, the SM is extended with only two additional fields, a singlet scalar that mixes with the Higgs boson, and the dark matter particle, a fermion assumed to be odd under a Z{sub 2} symmetry. After numerically studying the generation of dark matter, we analyze the dependence of the relic density with respect to all the free parameters of the model. These results are then used to obtain the regions of the parameter space that are compatible with the dark matter constraint. We demonstrate that the observed dark matter abundance can be explained via freeze-in over a wide range of masses extending down to the keV range. As a result, warm and cold dark matter can be obtained in this model. It is also possible to have dark matter masses well above the unitarity bound for WIMPs.

  7. Probing Light Dark Matter via Evaporation from the Sun

    E-Print Network [OSTI]

    Chris Kouvaris

    2015-06-13

    Dark matter particles can be captured by the sun with rates that depend on the dark matter mass and the DM-nucleon cross section. However, for masses below $\\sim 3.3$ GeV, the captured dark matter particles evaporate, leading to an equilibrium where the rate of captured particles is equal to the rate of evaporating ones. Unlike dark matter particles from the halo, the evaporating dark matter particles have velocities that are not limited to values below the escape velocity of the galaxy. Despite the fact that high velocities are exponentially suppressed, I demonstrate here that current underground detectors have the possibility to probe/constrain low dark matter parameter space by (not)-observing the high energy tail of the evaporating dark matter particles from the sun. I also show that the functional form of the differential rate of counts with respect to the recoil energy in earth based detectors can identify precisely the mass and the cross section of the dark matter particle in this case.

  8. Infinite statistics condensate as a model of dark matter

    SciTech Connect (OSTI)

    Ebadi, Zahra; Mirza, Behrouz; Mohammadzadeh, Hosein E-mail: b.mirza@cc.iut.ac.ir

    2013-11-01

    In some models, dark matter is considered as a condensate bosonic system. In this paper, we prove that condensation is also possible for particles that obey infinite statistics and derive the critical condensation temperature. We argue that a condensed state of a gas of very weakly interacting particles obeying infinite statistics could be considered as a consistent model of dark matter.

  9. Hunting for dark matter subhalos among the Fermi-LAT sources with VERITAS

    E-Print Network [OSTI]

    Nieto, Daniel

    2015-01-01

    The distribution of dark matter in the Galaxy, according to state-of-the-art simulations, shows not only a smooth halo component but also a rich substructure where a hierarchy of dark matter subhalos of different masses is found. We present a search for potential dark matter subhalos in our Galaxy exploiting the high (HE, 100 MeV -- 100 GeV) and very-high-energy (VHE, >100 GeV) gamma-ray bands. We assume a scenario where the dark matter is composed of weakly interacting massive particles of mass over 100 GeV, and is capable of self-annihilation into standard model products. Under such a hypothesis, most of the photons created by the annihilation of dark matter particles are predicted to lay in the HE gamma-ray band, where the Fermi-Large Area Telescope is the most sensitive instrument to date. However, the distinctive spectral cut-off located at the dark matter particle mass is expected in the VHE gamma-ray band, thus making imaging atmospheric Cherenkov telescopes like VERITAS the best suited instruments for...

  10. High-energy neutrino signals from the Sun in dark matter scenarios with internal bremsstrahlung

    SciTech Connect (OSTI)

    Ibarra, Alejandro; Totzauer, Maximilian; Wild, Sebastian E-mail: maximilian.totzauer@mytum.de

    2013-12-01

    We investigate the prospects to observe a high energy neutrino signal from dark matter annihilations in the Sun in scenarios where the dark matter is a Majorana fermion that couples to a quark and a colored scalar via a Yukawa coupling. In this minimal scenario, the dark matter capture and annihilation in the Sun can be studied in a single framework. We find that, for small and moderate mass splitting between the dark matter and the colored scalar, the two-to-three annihilation q q-bar g plays a central role in the calculation of the number of captured dark matter particles. On the other hand, the two-to-three annihilation into q q-bar Z gives, despite its small branching fraction, the largest contribution to the neutrino flux at the Earth at the highest energies. We calculate the limits on the model parameters using IceCube observations of the Sun and we discuss their interplay with the requirement of equilibrium of captures and annihilations in the Sun and with the requirement of thermal dark matter production. We also compare the limits from IceCube to the limits from direct detection, antiproton measurements and collider searches.

  11. Results on Dark Matter and beta beta decay modes by DAMA at Gran Sasso

    E-Print Network [OSTI]

    R. Bernabei

    2007-05-21

    DAMA is an observatory for rare processes and it is operative deep underground at the Gran Sasso National Laboratory of the I.N.F.N. (LNGS). Here some arguments will be presented on the investigation on dark matter particles by annual modulation signature and on some of the realized double beta decay searches.

  12. Low mass dark matter and invisible Higgs width in darkon models

    SciTech Connect (OSTI)

    Cai Yi; Ren Bo; He Xiaogang

    2011-04-15

    The Standard Model (SM) plus a real gauge-singlet scalar field dubbed darkon (SM+D) is the simplest model possessing a weakly interacting massive particle (WIMP) dark matter candidate. In this model, the parameters are constrained from dark matter relic density and direct searches. The fact that interaction between darkon and SM particles is only mediated by a Higgs boson exchange may lead to significant modifications to the Higgs boson properties. If the dark matter mass is smaller than half of the Higgs boson mass, then a Higgs boson can decay into a pair of darkons resulting in a large invisible branching ratio. The Higgs boson will be searched for at the LHC and may well be discovered in the near future. If a Higgs boson with a small invisible decay width will be found, the SM+D model with small dark matter mass will be in trouble. We find that by extending the SM+D to a two Higgs doublet model plus a darkon (THDM+D) it is possible to have a Higgs boson with a small invisible branching ratio and at the same time the dark matter can have a low mass. We also comment on other implications of this model.

  13. Update on the MiniCLEAN dark matter experiment

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rielage, K.; Akashi-Ronquest, M.; Bodmer, M.; Bourque, R.; Buck, B.; Butcher, A.; Caldwell, T.; Chen, Y.; Coakley, K.; Flores, E.; et al

    2015-03-24

    The direct search for dark matter is entering a period of increased sensitivity to the hypothetical Weakly Interacting Massive Particle (WIMP). One such technology that is being examined is a scintillation only noble liquid experiment, MiniCLEAN. MiniCLEAN utilizes over 500 kg of liquid cryogen to detect nuclear recoils from WIMP dark matter and serves as a demonstration for a future detector of order 50 to 100 tonnes. The liquid cryogen is interchangeable between argon and neon to study the A² dependence of the potential signal and examine backgrounds. MiniCLEAN utilizes a unique modular design with spherical geometry to maximize themore »light yield using cold photomultiplier tubes in a single-phase detector. Pulse shape discrimination techniques are used to separate nuclear recoil signals from electron recoil backgrounds. MiniCLEAN will be spiked with additional ³?Ar to demonstrate the effective reach of the pulse shape discrimination capability. Assembly of the experiment is underway at SNOLAB and an update on the project is given.« less

  14. MeV Dark Matter and Small Scale Structure

    SciTech Connect (OSTI)

    Hooper, Dan; /Fermilab; Kaplinghat, Manoj; Strigari, Louis E.; /UC, Irvine; Zurek, Kathryn M.; /Wisconsin U., Madison

    2007-04-01

    WIMPs with electroweak scale masses (neutralinos, etc.) remain in kinetic equilibrium with other particle species until temperatures approximately in the range of 10 MeV to 1 GeV, leading to the formation of dark matter substructure with masses as small as 10{sup -4} M{sub {circle_dot}} to 10{sup -12} M{sub {circle_dot}}. However, if dark matter consists of particles with MeV scale masses, as motivated by the observation of 511 keV emission from the Galactic Bulge, such particles are naturally expected to remain in kinetic equilibrium with the cosmic neutrino background until considerably later times. This would lead to a strong suppression of small scale structure with masses below about 10{sup 7}M{sub {circle_dot}} to 10{sup 4} M{sub {circle_dot}}. This cutoff scale has important implications for present and future searches for faint Local Group satellite galaxies and for the missing satellites problem.

  15. Properties of galactic dark matter: Constraints from astronomical observations

    SciTech Connect (OSTI)

    Burch, B.; Cowsik, R.

    2013-12-10

    The distributions of normal matter and of dark matter in the Galaxy are coupled to each other as they both move in the common gravitational potential. In order to fully exploit this interplay and to derive the various properties of dark matter relevant to their direct and indirect detection, we have comprehensively reviewed the astronomical observations of the spatial and velocity distributions of the components of normal matter. We then postulate that the phase-space distribution of dark matter follows a lowered-isothermal form and self-consistently solve Poisson's equation to construct several models for the spatial and velocity distributions of dark matter. In this paper, we compute the total gravitational potential of the normal and dark matter components and investigate their consistency with current observations of the rotation curve of the Galaxy and of the spatial and velocity distributions of blue horizontal-branch and blue straggler stars. Even with this demand of consistency, a large number of models with a range of parameters characterizing the dark matter distribution remain. We find that the best choice of parameters, within the range of allowed values for the surface density of the disk 55 M {sub ?} pc{sup –2}, are the following: the dark matter density at the Galactic center ?{sub DM,} {sub c} ? 100-250 GeV cm{sup –3}, the local dark matter density ?{sub DM}(R {sub 0}) ? 0.56-0.72 GeV cm{sup –3}, and the rms speed of dark matter particles ?v{sub DM}{sup 2}(R{sub 0})?{sup 1/2}?490??550 km s{sup –1}. We also discuss possible astronomical observations that may further limit the range of the allowed models. The predictions of the allowed models for direct and indirect detection will be discussed separately in a companion paper.

  16. Microlensing Implications for Halo Dark Matter

    E-Print Network [OSTI]

    Philippe Jetzer; Eduard Masso

    1996-01-23

    The most accurate way to get information on the mass of the MACHOs (Massive Astrophysical Compact Halo Objects) is to use the method of mass moments. For the microlensing events detected so far by the EROS and the MACHO collaborations in the Large Magellanic Cloud the average mass turns out to be 0.08$M_{\\odot}$. Assuming a spherical standard halo model we find that MACHOs contribute about 20\\% to the halo dark matter. The eleven events recorded by OGLE, mainly during its first two years of operation, in the galactic bulge lead to an average mass of 0.29$M_{\\odot}$, whereas forty events detected by MACHO during its first year give 0.16$M_{\\odot}$, thus suggesting that the lens objects are faint disk stars.

  17. Dark Matter and the Baryon Asymmetry

    E-Print Network [OSTI]

    Glennys R. Farrar; Gabrijela Zaharijas

    2005-10-06

    We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\mathcal{O}$(10%) or more, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$. Two concrete examples are given, one of which can be excluded on observational grounds.

  18. On the Segregation of Dark Matter Substructure

    E-Print Network [OSTI]

    Bosch, Frank C van den; Campbell, Duncan; Behroozi, Peter

    2015-01-01

    We present the first comprehensive analysis of the segregation of dark matter subhaloes in their host haloes. Using numerical simulations, we examine the segregation of twelve different subhalo properties with respect to both orbital energy and halo-centric radius (in real space as well as in projection). Subhaloes are strongly segregated by accretion redshift, which is an outcome of the inside-out assembly of their host haloes. Since subhaloes that were accreted earlier have experienced more tidal stripping, subhaloes that have lost a larger fraction of their mass at infall are on more bound orbits. Subhaloes are also strongly segregated in their masses and maximum circular velocities at accretion. We demonstrate that part of this segregation is already imprinted in the infall conditions. For massive subhaloes it is subsequently boosted by dynamical friction, but only during their first radial orbit. The impact of these two effects is counterbalanced, though, by the fact that subhaloes with larger accretion ...

  19. Cosmic Ray Protons Illuminate Dark Matter Axions

    E-Print Network [OSTI]

    H. Tam; Q. Yang

    2011-08-16

    Cosmic ray protons propagating in a spatially-homogeneous but time-dependent field of axions or axion-like particles (ALPs) emit photons in a way that is reminiscent of Cherenkov radiation by charged particles in a preferred background. We compute the emission rate and energy spectrum of the photons, and discuss the possibility of their detection using the Square Kilometre Array which is currently under construction. In the case of a non-detection, constraints can be placed on the parameter space of ALPs whose mass lie between $10^{-7}$eV and $10^{-5}$ eV under the assumption that they are the primary constituent of dark matter.

  20. The positron excess and supersymmetric dark matter

    E-Print Network [OSTI]

    Edward A. Baltz; Joakim Edsjo; Katherine Freese; Paolo Gondolo

    2002-11-12

    Using a new instrument, the HEAT collaboration has confirmed the excess of cosmic ray positrons that they first detected in 1994. We explore the possibility that this excess is due to the annihilation of neutralino dark matter in the galactic halo. We confirm that neutralino annihilation can produce enough positrons to make up the measured excess only if there is an additional enhancement to the signal. We quantify the `boost factor' that is required in the signal for various models in the Minimal Supersymmetric Standard Model parameter space, and find that a boost factor >30 provides good fits to the HEAT data. Such an enhancement in the signal could arise if we live in a clumpy halo.

  1. LHC prospects for minimal decaying dark matter

    SciTech Connect (OSTI)

    Arcadi, Giorgio; Covi, Laura; Dradi, Federico, E-mail: giorgio.arcadi@theorie.physik.uni-goettingen.de, E-mail: laura.covi@theorie.physik.uni-goettingen.de, E-mail: federico.dradi@theorie.physik.uni-goettingen.de [Institute for Theoretical Physics, Georg-August University Göttingen, Friedrich-Hund-Platz 1, Göttingen, D-37077 Germany (Germany)

    2014-10-01

    We study the possible signals at LHC of the minimal models of decaying dark matter. Those models are characterized by the fact that DM interacts with SM particles through renormalizable coupling with an additional heavier charged state. Such interaction allows to produce a substantial abundance of DM in the early Universe via the decay of the charged heavy state, either in- or out-of-equilibrium. Moreover additional couplings of the charged particle open up decay channels for the DM, which can nevertheless be sufficiently long-lived to be a good DM candidate and within reach of future Indirect Detection observations. We compare the cosmologically favored parameter regions to the LHC discovery reach and discuss the possibility of simultaneous detection of DM decay in Indirect Detection.

  2. Atomic ionization by keV-scale pseudoscalar dark-matter particles

    SciTech Connect (OSTI)

    Dzuba, V. A.; Flambaum, V. V.; Pospelov, M.

    2010-05-15

    Using the relativistic Hartree-Fock approximation, we calculate the rates of atomic ionization by absorption of pseudoscalar particles in the mass range from 10 to {approx}50 keV. We present numerical results for atoms relevant for the direct dark-matter searches (e.g. Ar, Ge, I and Xe), as well as the analytical formula which fits numerical calculations with few per cent accuracy and may be used for multielectron atoms, molecules and condensed matter systems.

  3. Pulsar timing signal from ultralight scalar dark matter

    SciTech Connect (OSTI)

    Khmelnitsky, Andrei; Rubakov, Valery E-mail: rubakov@ms2.inr.ac.ru

    2014-02-01

    An ultralight free scalar field with mass around 10{sup ?23}?10{sup ?22} eV is a viable dark mater candidate, which can help to resolve some of the issues of the cold dark matter on sub-galactic scales. We consider the gravitational field of the galactic halo composed out of such dark matter. The scalar field has oscillating in time pressure, which induces oscillations of gravitational potential with amplitude of the order of 10{sup ?15} and frequency in the nanohertz range. This frequency is in the range of pulsar timing array observations. We estimate the magnitude of the pulse arrival time residuals induced by the oscillating gravitational potential. We find that for a range of dark matter masses, the scalar field dark matter signal is comparable to the stochastic gravitational wave signal and can be detected by the planned SKA pulsar timing array experiment.

  4. Evidence for dark matter interactions in cosmological precision data?

    E-Print Network [OSTI]

    Lesgourgues, Julien; Schmaltz, Martin

    2015-01-01

    We study a two-parameter extension of the cosmological standard model $\\Lambda$CDM in which cold dark matter interacts with a new form of dark radiation. The two parameters correspond to the energy density in the dark radiation $\\Delta N_\\mathrm{eff}$ and the interaction strength between the dark matter and dark radiation fluids. The interactions give rise to a very weak "dark matter drag" which damps the growth of matter density perturbations throughout radiation domination, allowing to reconcile the tension between predictions of large scale structure from the CMB and direct measurements of $\\sigma_8$. We perform a precision fit to Planck CMB data, BAO, large scale structure, and direct measurements of the expansion rate of the universe today. Our model lowers the $\\chi$-squared relative to $\\Lambda$CDM by about 11, corresponding to a preference for non-zero dark matter drag by more than $3 \\sigma$. Particle physics models which naturally produce a dark matter drag of the required form include the recently ...

  5. Integrating in the Higgs Portal to Fermion Dark Matter

    E-Print Network [OSTI]

    Ayres Freitas; Susanne Westhoff; Jure Zupan

    2015-06-23

    Fermion dark matter (DM) interacting with the standard model through a Higgs portal requires non-renormalizable operators, signaling the presence of new mediator states at the electroweak scale. Collider signatures that involve the mediators are a powerful tool to experimentally probe the Higgs portal interactions, providing complementary information to strong constraints set by direct DM detection searches. Indirect detection experiments are less sensitive to this scenario. We investigate the collider reach for the mediators using three minimal renormalizable models as examples, and requiring the fermion DM to be a thermal relic. The Large Hadron Collider in its high-energy, high-luminosity phase can probe most scenarios if DM is lighter than about 200 GeV. Beyond this scale, future high-energy experiments such as an electron-positron collider or a 100-TeV proton-proton collider, combined with future direct detection experiments, are indispensable to conclusively test these models.

  6. Superconducting Radio Frequency Cavities as Axion Dark Matter Detectors

    E-Print Network [OSTI]

    P. Sikivie

    2013-01-20

    A modification of the cavity technique for axion dark matter detection is described in which the cavity is driven with input power instead of being permeated by a static magnetic field. A small fraction of the input power is pumped by the axion field to a receiving mode of frequency $\\omega_1$ when the resonance condition $\\omega_1 = \\omega_0 \\pm m_a$ is satisfied, where $\\omega_0$ is the frequency of the input mode and $m_a$ the axion mass. The relevant form factor is calculated for any pair of input and output modes in a cylindrical cavity. The overall search strategy is discussed and the technical challenges to be overcome by an actual experiment are listed.

  7. Exploring dark matter microphysics with galaxy surveys

    E-Print Network [OSTI]

    Escudero, Miguel; Vincent, Aaron C; Wilkinson, Ryan J; Boehm, Celine

    2015-01-01

    We use present cosmological observations and forecasts of future experiments to illustrate the power of large-scale structure (LSS) surveys in probing dark matter (DM) microphysics and unveiling potential deviations from the standard $\\Lambda$CDM scenario. To quantify this statement, we focus on an extension of $\\Lambda$CDM with DM-neutrino scattering, which leaves a distinctive imprint on the angular and matter power spectra. After finding that future CMB experiments (such as COrE+) will not significantly improve the constraints set by the Planck satellite, we show that the next generation of galaxy clustering surveys (such as DESI) could play a leading role in constraining alternative cosmologies and even have the potential to make a discovery. Typically, we find that DESI would be an order of magnitude more sensitive to DM interactions than Planck (if s-wave) and two orders of magnitude (if p-wave), thus probing effects that until now have only been accessible via N-body simulations.

  8. Axion hot dark matter bounds after Planck

    SciTech Connect (OSTI)

    Archidiacono, Maria; Hannestad, Steen; Mirizzi, Alessandro; Raffelt, Georg; Wong, Yvonne Y.Y. E-mail: sth@phys.au.dk E-mail: raffelt@mpp.mpg.de

    2013-10-01

    We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an upper limit m{sub a} < 0.67 eV at 95% C.L. after marginalising over the unknown neutrino masses, using CMB temperature and polarisation data from Planck and WMAP respectively, the halo matter power spectrum extracted from SDSS-DR7, and the local Hubble expansion rate H{sub 0} released by the Carnegie Hubble Program based on a recalibration of the Hubble Space Telescope Key Project sample. Leaving out the local H{sub 0} measurement relaxes the limit somewhat to 0.86 eV, while Planck+WMAP alone constrain the axion mass to 1.01 eV, the first time an upper limit on m{sub a} has been obtained from CMB data alone. Our axion limit is therefore not very sensitive to the tension between the Planck-inferred H{sub 0} and the locally measured value. This is in contrast with the upper limit on the neutrino mass sum, which we find here to range from ? m{sub ?} < 0.27 eV at 95% C.L. combining all of the aforementioned observations, to 0.84 eV from CMB data alone.

  9. Isospin violating dark matter in Stückelberg portal scenarios

    E-Print Network [OSTI]

    Victor Martin-Lozano; Miguel Peiro; Pablo Soler

    2015-03-05

    Hidden sector scenarios in which dark matter (DM) interacts with the Standard Model matter fields through the exchange of massive Z' bosons are well motivated by certain string theory constructions. In this work, we thoroughly study the phenomenological aspects of such scenarios and find that they present a clear and testable consequence for direct DM searches. We show that such string motivated St\\"uckelberg portals naturally lead to isospin violating interactions of DM particles with nuclei. We find that the relations between the DM coupling to neutrons and protons for both, spin-independent (fn/fp) and spin-dependent (an/ap) interactions, are very flexible depending on the charges of the quarks under the extra U(1) gauge groups. We show that within this construction these ratios are generically different from plus and minus 1 (i.e. different couplings to protons and neutrons) leading to a potentially measurable distinction from other popular portals. Finally, we incorporate bounds from searches for dijet and dilepton resonances at the LHC as well as LUX bounds on the elastic scattering of DM off nucleons to determine the experimentally allowed values of fn/fp and an/ap.

  10. Diurnal modulation signal from dissipative hidden sector dark matter

    E-Print Network [OSTI]

    R. Foot; S. Vagnozzi

    2015-06-07

    We consider a simple generic dissipative dark matter model: a hidden sector featuring two dark matter particles charged under an unbroken $U(1)'$ interaction. Previous work has shown that such a model has the potential to explain dark matter phenomena on both large and small scales. In this framework, the dark matter halo in spiral galaxies features nontrivial dynamics, with the halo energy loss due to dissipative interactions balanced by a heat source. Ordinary supernovae can potentially supply this heat provided kinetic mixing interaction exists with strength $\\epsilon \\sim 10^{-9}$. This type of kinetically mixed dark matter can be probed in direct detection experiments. Importantly, this self-interacting dark matter can be captured within the Earth and shield a dark matter detector from the halo wind, giving rise to a diurnal modulation effect. We estimate the size of this effect for detectors located in the Southern hemisphere, and find that the modulation is large ($\\gtrsim 10\\%$) for a wide range of parameters.

  11. Indirect Detection of Dark Matter in km-size Neutrino Telescopes

    E-Print Network [OSTI]

    Lars Bergstrom; Joakim Edsjo; Paolo Gondolo

    1999-06-02

    Neutrino telescopes of kilometer size are currently being planned. They will be two or three orders of magnitude larger than presently operating detectors, but they will have a much higher muon energy threshold. We discuss the trade-off between area and energy threshold for indirect detection of neutralino dark matter captured in the Sun and in the Earth and annihilating into high energy neutrinos. We also study the effect of a higher threshold on the complementarity of different searches for supersymmetric dark matter.

  12. Constraints on particle dark matter from cosmic-ray antiprotons

    E-Print Network [OSTI]

    N. Fornengo; L. Maccione; A. Vittino

    2015-01-30

    Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are significantly strong, setting a lower bound on the dark matter mass of a "thermal" relic at about 50-90 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 4-5 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modeling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints.

  13. Solving the dark matter problem by dynamic interactions

    E-Print Network [OSTI]

    Hofer, Werner A

    2015-01-01

    Due to the renewed interest in dark matter after the upgrade of the large hadron collider and its dedication to dark matter research it is timely to reassess the whole problem. Dark matter is one way to reconcile the discrepancy between the velocity of matter in the outer regions of galaxies and the observed galactic mass. So far, no credible candidate for dark matter has been identified. Here, we develop a model accounting for observations by rotations and interactions between rotating objects analogous to magnetic fields and interactions with moving charges. The magnitude of these fields is described by a fundamental constant of the order 10-41kg-1. The same interactions can be observed in the solar system where they lead to small changes of planetary orbits.

  14. Sensitivity of IceCube-DeepCore to neutralino dark matter in the MSSM-25

    E-Print Network [OSTI]

    Hamish Silverwood; Pat Scott; Matthias Danninger; Christopher Savage; Joakim Edsjö; Jenni Adams; Anthony M Brown; Klas Hultqvist

    2013-04-17

    We analyse the sensitivity of IceCube-DeepCore to annihilation of neutralino dark matter in the solar core, generated within a 25 parameter version of the minimally supersymmetric standard model (MSSM-25). We explore the 25-dimensional parameter space using scanning methods based on importance sampling and using DarkSUSY 5.0.6 to calculate observables. Our scans produced a database of 6.02 million parameter space points with neutralino dark matter consistent with the relic density implied by WMAP 7-year data, as well as with accelerator searches. We performed a model exclusion analysis upon these points using the expected capabilities of the IceCube-DeepCore Neutrino Telescope. We show that IceCube-DeepCore will be sensitive to a number of models that are not accessible to direct detection experiments such as SIMPLE, COUPP and XENON100, indirect detection using Fermi-LAT observations of dwarf spheroidal galaxies, nor to current LHC searches.

  15. Sensitivity of IceCube-DeepCore to neutralino dark matter in the MSSM-25

    SciTech Connect (OSTI)

    Silverwood, Hamish; Adams, Jenni; Brown, Anthony M; Scott, Pat; Danninger, Matthias; Savage, Christopher; Edsjö, Joakim; Hultqvist, Klas E-mail: patscott@physics.mcgill.ca E-mail: savage@physics.utah.edu E-mail: jenni.adams@canterbury.ac.nz E-mail: klas.hultqvist@fysik.su.se

    2013-03-01

    We analyse the sensitivity of IceCube-DeepCore to annihilation of neutralino dark matter in the solar core, generated within a 25 parameter version of the minimally supersymmetric standard model (MSSM-25). We explore the 25-dimensional parameter space using scanning methods based on importance sampling and using DarkSUSY 5.0.6 to calculate observables. Our scans produced a database of 6.02 million parameter space points with neutralino dark matter consistent with the relic density implied by WMAP 7-year data, as well as with accelerator searches. We performed a model exclusion analysis upon these points using the expected capabilities of the IceCube-DeepCore Neutrino Telescope. We show that IceCube-DeepCore will be sensitive to a number of models that are not accessible to direct detection experiments such as SIMPLE, COUPP and XENON100, indirect detection using Fermi-LAT observations of dwarf spheroidal galaxies, nor to current LHC searches.

  16. Bose-Einstein Condensation of Dark Matter Axions

    E-Print Network [OSTI]

    P. Sikivie; Q. Yang

    2009-09-02

    We show that cold dark matter axions thermalize and form a Bose-Einstein condensate. We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles.

  17. Towards the Final Word on Neutralino Dark Matter

    E-Print Network [OSTI]

    Bramante, Joseph; Fox, Patrick; Martin, Adam; Ostdiek, Bryan; Plehn, Tilman

    2015-01-01

    We present a complete phenomenological prospectus for thermal relic neutralinos. Including Sommerfeld enhancements to relic abundance and halo annihilation calculations, we obtain direct, indirect, and collider discovery prospects for all neutralinos with mass parameters $M_1,M_2,|\\mu| < 4$ TeV, that freeze out to the observed dark matter abundance, with scalar superpartners decoupled. Much of the relic neutralino sector will be uncovered by the direct detection experiments Xenon1T and LZ, as well as indirect detection with CTA. We emphasize that thermal relic higgsinos will be found by next-generation direct detection experiments, so long as $M_{1,2} < 4$ TeV. Charged tracks at a 100 TeV hadron collider complement indirect searches for relic winos. Thermal relic bino-winos still evade all planned experiments, including disappearing charged-track searches. However, they can be discovered by compressed electroweakino searches at a 100 TeV collider, completing the full coverage of the relic neutralino sur...

  18. Cogenerating and Pre-annihilating Dark Matter by a New Gauge Interaction

    E-Print Network [OSTI]

    S. M. Barr; Robert J. Scherrer

    2015-12-12

    In asymmetric dark matter scenarios, there must be a mechanism to annihilate the anti-dark matter. It is proposed here that a new non-abelian gauge interaction can both cogenerate asymmetric dark matter with baryonic matter through its sphaleron processes, and can pre-annihilate the anti-dark matter efficiently. The resulting scenario can naturally generate either cold or warm dark matter.

  19. Cogenerating and Pre-annihilating Dark Matter by a New Gauge Interaction

    E-Print Network [OSTI]

    Barr, S M

    2015-01-01

    In asymmetric dark matter scenarios, there must be a mechanism to annihilate the anti-dark matter. It is proposed here that a new non-abelian gauge interaction can both cogenerate asymmetric dark matter with baryonic matter through its sphaleron processes, and can pre-annihilate the anti-dark matter efficiently. The resulting scenario can naturally generate either cold or warm dark matter.

  20. Dark matter and alternative recipes for the missing mass

    E-Print Network [OSTI]

    Crescenzo Tortora; Philippe Jetzer; Nicola R. Napolitano

    2012-02-03

    Within the standard cosmological scenario the Universe is found to be filled by obscure components (dark matter and dark energy) for ~95% of its energy budget. In particular, almost all the matter content in the Universe is given by dark matter, which dominates the mass budget and drives the dynamics of galaxies and clusters of galaxies. Unfortunately, dark matter and dark energy have not been detected and no direct or indirected observations have allowed to prove their existence and amount. For this reason, some authors have suggested that a modification of Einstein Relativity or the change of the Newton's dynamics law (within a relativistic and classical framework, respectively) could allow to replace these unobserved components. We will start discussing the role of dark matter in the early-type galaxies, mainly in their central regions, investigating how its content changes as a function of the mass and the size of each galaxy and few considerations about the stellar Initial mass function have been made. In the second part of the paper we have described, as examples, some ways to overcome the dark matter hypothesis, by fitting to the observations the modified dynamics coming out from general relativistic extended theories and the MOdyfied Newtonian dynamics (MOND).

  1. Dynamical system analysis for DBI dark energy interacting with dark matter

    E-Print Network [OSTI]

    Nilanjana Mahata; Subenoy Chakraborty

    2015-01-19

    A dynamical system analysis related to Dirac Born Infeld (DBI) cosmological model has been investigated in this present work. For spatially flat FRW space time, the Einstein field equation for DBI scenario has been used to study the dynamics of DBI dark energy interacting with dark matter. The DBI dark energy model is considered as a scalar field with a nonstandard kinetic energy term. An interaction between the DBI dark energy and dark matter is considered through a phenomenological interaction between DBI scalar field and the dark matter fluid. The field equations are reduced to an autonomous dynamical system by a suitable redefinition of the basic variables. The potential of the DBI scalar field is assumed to be exponential. Finally, critical points are determined, their nature have been analyzed and corresponding cosmological scenario has been discussed.

  2. Phase Space Dynamics of Non-Gravitational Interactions between Dark Matter and Dark Energy: The Case of Ghost Dark Energy

    E-Print Network [OSTI]

    Ricardo Garcia-Salcedo; Tame Gonzalez; Israel Quiros

    2012-11-15

    We study the phase space asymptotics of the so called Veneziano ghost dark energy models. Models where the ghost field's energy density: i) $\\rho_{ghost}\\propto H$, and ii) $\\rho_{ghost}\\propto H+H^2$, are investigated. Both, cases with and without additional non-gravitational interaction between cold dark matter and ghost dark energy, are subject to scrutiny. We pay special attention to the choice of phase space variables leading to bounded and compact phase space so that no critical point of physical interest is missing. A rich asymptotic structure is revealed: depending on the kind of non-minimal coupling critical points associated with radiation dominance, matter dominance, cold dark matter/ghost dark energy scaling, and ghost dark energy dominance, are found. Past and future attractors, as well as saddle equilibrium points, are identified in the corresponding phase spaces.

  3. Dark Photons from the Center of the Earth: Smoking-Gun Signals of Dark Matter

    E-Print Network [OSTI]

    Jonathan L. Feng; Jordan Smolinsky; Philip Tanedo

    2015-09-24

    Dark matter may be charged under dark electromagnetism with a dark photon that kinetically mixes with the Standard Model photon. In this framework, dark matter will collect at the center of the Earth and annihilate into dark photons, which may reach the surface of the Earth and decay into observable particles. We determine the resulting signal rates, including Sommerfeld enhancements, which play an important role in bringing the Earth's dark matter population to their maximal, equilibrium value. For dark matter masses $m_X \\sim$ 100 GeV - 10 TeV, dark photon masses $m_{A'} \\sim$ MeV - GeV, and kinetic mixing parameters $\\varepsilon \\sim 10^{-9} - 10^{-7}$, the resulting electrons, muons, photons, and hadrons that point back to the center of the Earth are a smoking-gun signal of dark matter that may be detected by a variety of experiments, including neutrino telescopes, such as IceCube, and space-based cosmic ray detectors, such as Fermi-LAT and AMS. We determine the signal rates and characteristics, and show that large and striking signals---such as parallel muon tracks---are possible in regions of the $(m_{A'}, \\varepsilon)$ plane that are not probed by direct detection, accelerator experiments, or astrophysical observations.

  4. Dark Photons from the Center of the Earth: Smoking-Gun Signals of Dark Matter

    E-Print Network [OSTI]

    Feng, Jonathan L; Tanedo, Philip

    2015-01-01

    Dark matter may be charged under dark electromagnetism with a dark photon that kinetically mixes with the Standard Model photon. In this framework, dark matter will collect at the center of the Earth and annihilate into dark photons, which may reach the surface of the Earth and decay into observable particles. We determine the resulting signal rates, including Sommerfeld enhancements, which play an important role in bringing the Earth's dark matter population to their maximal, equilibrium value. For dark matter masses $m_X \\sim$ 100 GeV - 10 TeV, dark photon masses $m_{A'} \\sim$ MeV - GeV, and kinetic mixing parameters $\\varepsilon \\sim 10^{-9} - 10^{-7}$, the resulting electrons, muons, photons, and hadrons that point back to the center of the Earth are a smoking-gun signal of dark matter that may be detected by a variety of experiments, including neutrino telescopes, such as IceCube, and space-based cosmic ray detectors, such as Fermi-LAT and AMS. We determine the signal rates and characteristics, and show ...

  5. Review of the theoretical and experimental status of dark matter identification with cosmic-ray antideuterons

    E-Print Network [OSTI]

    T. Aramaki; S. Boggs; S. Bufalino; L. Dal; P. von Doetinchem; F. Donato; N. Fornengo; H. Fuke; M. Grefe; C. Hailey; B. Hamilton; A. Ibarra; J. Mitchell; I. Mognet; R. A. Ong; R. Pereira; K. Perez; A. Putze; A. Raklev; P. Salati; M. Sasaki; G. Tarle; A. Urbano; A. Vittino; S. Wild; W. Xue; K. Yoshimura

    2015-05-28

    Recent years have seen increased theoretical and experimental effort towards the first-ever detection of cosmic-ray antideuterons, in particular as an indirect signature of dark matter annihilation or decay. In contrast to indirect dark matter searches using positrons, antiprotons, or gamma-rays, which suffer from relatively high and uncertain astrophysical backgrounds, searches with antideuterons benefit from very suppressed conventional backgrounds, offering a potential breakthrough in unexplored phase space for dark matter. This article is based on the first dedicated cosmic-ray antideuteron workshop, which was held at UCLA in June 2014. It reviews broad classes of dark matter candidates that result in detectable cosmic-ray antideuteron fluxes, as well as the status and prospects of current experimental searches. The coalescence model of antideuteron production and the influence of antideuteron measurements at particle colliders are discussed. This is followed by a review of the modeling of antideuteron propagation through the magnetic fields, plasma currents, and molecular material of our Galaxy, the solar system, the Earth's geomagnetic field, and the atmosphere. Finally, the three ongoing or planned experiments that are sensitive to cosmic-ray antideuterons, BESS, AMS-02, and GAPS, are detailed. As cosmic-ray antideuteron detection is a rare event search, multiple experiments with orthogonal techniques and backgrounds are essential. Many theoretical and experimental groups have contributed to these studies over the last decade, this review aims to provide the first coherent discussion of the relevant dark matter theories that antideuterons probe, the challenges to predictions and interpretations of antideuteron signals, and the experimental efforts toward cosmic antideuteron detection.

  6. Galactic Center gamma-ray excess and Higgs-portal Dark Matter

    E-Print Network [OSTI]

    Tanmoy Mondal; Tanushree Basak

    2015-07-07

    From astronomical observations, we know that dark matter exists and makes up $\\sim$25\\% of our Universe. Recently the study of anomalous gamma-ray emission in the regions surrounding the galactic center has drawn a lot of attention. It has been pointed out that the excess of 1-3 GeV gamma-ray in the low latitude is consistent with the emission expected from annihilating dark matter. I will discuss the Higgs-portal dark matter models which can explain these phenomena because of the presence of scalar resonance. In addition, the parameter space of these models also satisfy constraints from the LHC Higgs searches, relic abundance and direct detection experiments. The gauged $U(1)_{B-L}$ model is very well suited with the FERMI-LAT observation along with other constraints.

  7. Radon backgrounds in the DRIFT-II directional dark matter experiments

    E-Print Network [OSTI]

    Daw, E; Gauvreau, J -L; Gold, M; Harmon, L J; Landers, J M; Lee, E R; Loomba, D; Miller, E H; Murphy, A StJ; Paling, S M; Pipe, M; Robinson, M; Sadler, S; Scarff, A; Snowden-Ifft, D P; Spooner, N J C; Walker, D

    2013-01-01

    Low pressure gas Time Projection Chambers being developed for directional Dark Matter searches offer a technology with high particle identification power, combined with poten- tial to produce a definitive detection of galactic Weakly Interacting Massive Particle (WIMP) Dark Matter. A source of background events in such experiments, able to mimic genuine WIMP in- duced nuclear recoil tracks, arises from potential radon contamination and the recoils that result from associated daughter nuclei, termed Radon Progeny Recoils (RPRs). We present here experi- mental data from a long-term study of this background using the DRIFT-II directional dark matter experiment at the Boulby Underground Laboratory. By detailed examination of event classes in both spatial and time coordinates using 5.5 years of data we show ability to determine the origin of 4 specific background populations and describe development of new technology and mitigation strategies to suppress them.

  8. Diffusion of dark matter in a hot and dense nuclear environment

    E-Print Network [OSTI]

    Cermeño, Marina; Silk, Joseph

    2015-01-01

    We calculate the mean free path in a hot and dense nuclear environment for a fermionic dark matter particle candidate interacting with nucleons via scalar and vector couplings. We determine the effects of density and temperature in the medium by using nuclear distribution functions to size the importance of the final state blocking. Our results show that stellar nuclear scenarios, where dark matter may be accreted, provide opacities several orders of magnitude larger than those for Standard Model neutrinos in the context of cooling of proto-neutron stars. We also show that in a diffusive approximation with couplings of Fermi's constant strength the obtained dark matter-nucleon crosss sections display the same sensitivity that upper limits constrained with collider searches in the mass region $m_\\chi \\lesssim$ 5 GeV.

  9. Toward the full test of the nuMSM sterile neutrino dark matter model with Athena

    E-Print Network [OSTI]

    Neronov, A

    2015-01-01

    We discuss the potential of Athena X-ray telescope, in particular of its X-ray Integral Field Unit (X-IFU), for detection of the signal from the light-weight decaying dark matter with mass in the keV range. We show that high energy resolution and large collection area of X-IFU will provide an improvement of sensitivity which will be sufficient for the full test of the neutrino Minimal extension of the Standard Model (nuMSM). Search for the narrow spectral line produced by the decay of the dark matter sterile neutrino in the spectra of dwarf spheroidal galaxies with X-IFU will explore the whole allowed range masses and mixing angles of the nuMSM lightest sterile neutrino and in this way either to find the dark matter signal or rule out the nuMSM model.

  10. Influences of Dark Energy and dark matter on Gravitational Time Advancement

    E-Print Network [OSTI]

    Ghosh, Samrat

    2015-01-01

    The effect of dark matter/energy on gravitational time advancement (negative effective time delay) has been investigated considering few dark energy/matter models including cosmological constant. It is found that dark energy gives only (positive) gravitational time delay irrespective of the position of the observer whereas pure Schwarzschild geometry leads to gravitational time advancement when the observer is situated at relatively stronger gravitational field point in the light trajectory. Consequently, there will be no time advancement effect at all at radial distances where gravitational field due to dark energy is stronger than the gravitational field of Schwarzschild geometry.

  11. Study of alpha background in a dark matter detector

    E-Print Network [OSTI]

    Yegoryan, Hayk

    2010-01-01

    Alpha background, specifically from radon and its progeny in the uranium and thorium chains, has been a major issue in dark matter detectors. This work focuses on alpha background presence in the DMTPC experiment by examining ...

  12. Detecting electron neutrinos from solar dark matter annihilation by JUNO

    E-Print Network [OSTI]

    Guo, Wan-Lei

    2015-01-01

    We explore the electron neutrino signals from light dark matter (DM) annihilation in the Sun for the large liquid scintillator detector JUNO. In terms of the spectrum features of three typical DM annihilation channels $\\chi \\chi \\rightarrow \

  13. Modulation Effects in Dark Matter-Electron Scattering Experiments

    E-Print Network [OSTI]

    Lee, Samuel K; Mishra-Sharma, Siddharth; Safdi, Benjamin R

    2015-01-01

    One of the next frontiers in dark-matter direct-detection experiments is to explore the MeV to GeV mass regime. Such light dark matter does not carry enough kinetic energy to produce an observable nuclear recoil, but it can scatter off electrons, leading to a measurable signal. We introduce a semi-analytic approach to characterize the resulting electron-scattering events in atomic and semiconductor targets, improving on previous analytic proposals that underestimate the signal at high recoil energies. We then use this procedure to study the time-dependent properties of the electron-scattering signal, including the modulation fraction, higher-harmonic modes and modulation phase. The time dependence can be distinct in a non-trivial way from the nuclear scattering case. Additionally, we show that dark-matter interactions inside the Earth can significantly distort the lab-frame phase-space distribution of sub-GeV dark matter.

  14. Abundance of Asymmetric Dark Matter in Brane World Cosmology

    E-Print Network [OSTI]

    Hoernisa Iminniyaz

    2015-05-14

    Relic abundance of asymmetric Dark Matter particles in brane world cosmological scenario is investigated in this article. Hubble expansion rate is enhanced in brane world cosmology and it affects the relic abundance of asymmetric Dark Matter particles. We analyze how the relic abundance of asymmetric Dark Matter is changed in this model. We show that in such kind of nonstandard cosmological scenario, indirect detection of asymmetric Dark Matter is possible if the cross section is small enough which let the anti--particle abundance kept in the same amount with the particle. We show the indirect detection signal like Fermi--LAT constraints can be used to such model only when the cross section and the 5 dimensional Planck mass scale are in appropriate values.

  15. Light Higgses and Dark Matter Bob McElrath

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    , making DAMA more sensitive to light dark matter. Furthermore, a "wind" passing through our local region not produce any 0 or high-energy photons from e+e- final state, due to COMPTEL and EGRET limits on gamma rays

  16. Dark matter: the next great discovery of particle physics?: Ettore...

    Office of Scientific and Technical Information (OSTI)

    in the Standard Model. Dark matter is necessary for the formation of galaxies and galaxy clusters and hence has shaped the Universe as we know it. Despite this body of...

  17. An antenna for directional detection of WISPy dark matter

    SciTech Connect (OSTI)

    Jaeckel, Joerg; Redondo, Javier E-mail: redondo@mpp.mpg.de

    2013-11-01

    It is an intriguing possibility that the cold dark matter of the Universe may consist of very light and very weakly interacting particles such as axion(-like particles) and hidden photons. This opens up (but also requires) new techniques for direct detection. One possibility is to use reflecting surfaces to facilitate the conversion of dark matter into photons, which can be concentrated in a detector with a suitable geometry. In this note we show that this technique also allows for directional detection and inference of the full vectorial velocity spectrum of the dark matter particles. We also note that the non-vanishing velocity of dark matter particles is relevant for the conception of (non-directional) discovery experiments and outline relevant features.

  18. The Sensitivity of HAWC to High-Mass Dark Matter Annihilations

    E-Print Network [OSTI]

    Abeysekara, A U; Alvarez, C; Álvarez, J D; Arceo, R; Arteaga-Velázquez, J C; Solares, H A Ayala; Barber, A S; Baughman, B M; Bautista-Elivar, N; Gonzalez, J Becerra; Belmont, E; BenZvi, S Y; Berley, D; Rosales, M Bonilla; Braun, J; Caballero-Lopez, R A; Caballero-Mora, K S; Carramiñana, A; Castillo, M; Cotti, U; Cotzomi, J; de la Fuente, E; De León, C; DeYoung, T; Hernandez, R Diaz; Diaz-Cruz, L; D\\'\\iaz-Vélez, J C; Dingus, B L; DuVernois, M A; Ellsworth, R W; E., S F; Fiorino, D W; Fraija, N; Galindo, A; Garfias, F; González, M M; Goodman, J A; Grabski, V; Gussert, M; Hampel-Arias, Z; Harding, J P; Hui, C M; Hüntemeyer, P; Imran, A; Iriarte, A; Karn, P; Kieda, D; Kunde, G J; Lara, A; Lauer, R J; Lee, W H; Lennarz, D; Vargas, H León; Linares, E C; Linnemann, J T; Longo, M; Luna-Garcia, R; Marinelli, A; Martinez, H; Martinez, O; Mart\\'\\inez-Castro, J; Matthews, J A J; McEnery, J; Torres, E Mendoza; Miranda-Romagnoli, P; Moreno, E; Mostafá, M; Nellen, L; Newbold, M; Noriega-Papaqui, R; Oceguera-Becerra, T; Patricelli, B; Pelayo, R; Pérez-Pérez, E G; Pretz, J; Rivière, C; Rosa-González, D; Ryan, J; Salazar, H; Salesa, F; Sandoval, A; Schneider, M; Silich, S; Sinnis, G; Smith, A J; Woodle, K Sparks; Springer, R W; Taboada, I; Toale, P A; Tollefson, K; Torres, I; Ukwatta, T N; Villaseñor, L; Weisgarber, T; Westerhoff, S; Wisher, I G; Wood, J; Yodh, G B; Younk, P W; Zaborov, D; Zepeda, A; Zhou, H; Abazajian, K N

    2014-01-01

    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Summer 2014. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi-TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dar...

  19. Leptophilic dark matter and the anomalous magnetic moment of the muon

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Agrawal, Prateek; Chacko, Zackaria; Verhaaren, Christopher B.

    2014-08-26

    We consider renormalizable theories such that the scattering of dark matter off leptons arises at tree level, but scattering off nuclei only arises at loop. In this framework, the various dark matter candidates can be classified by their spins and by the forms of their interactions with leptons. In this study, we determine the corrections to the anomalous magnetic moment of the muon that arise from its interactions with dark matter. We then consider the implications of these results for a set of simplified models of leptophilic dark matter. When a dark matter candidate reduces the existing tension between themore »standard model prediction of the anomalous magnetic moment and the experimental measurement, the region of parameter space favored to completely remove the discrepancy is highlighted. Conversely, when agreement is worsened, we place limits on the parameters of the corresponding simplified model. These bounds and favored regions are compared against the experimental constraints on the simplified model from direct detection and from collider searches. Although these constraints are severe, we find there do exist limited regions of parameter space in these simple theories that can explain the observed anomaly in the muon magnetic moment while remaining consistent with all experimental bounds.« less

  20. Direct Detection of Dark Matter with MadDM v.2.0

    E-Print Network [OSTI]

    Mihailo Backovic; Kyoungchul Kong; Antony Martini; Olivier Mattelaer; Gopolang Mohlabeng

    2015-05-15

    We present MadDM v.2.0, a numerical tool for dark matter physics in a generic model. This version is the next step towards the development of a fully automated framework for dark matter searches at the interface of collider physics, astro-physics and cosmology. It extends the capabilities of v.1.0 to perform calculations relevant to the direct detection of dark matter. These include calculations of spin-independent/spin-dependent nucleon scattering cross sections and nuclear recoil rates (as a function of both energy and angle), as well as a simplified functionality to compare the model points with existing constraints. The functionality of MadDM v.2.0 incorporates a large selection of dark matter detector materials and sizes, and simulates detector effects on the nuclear recoil signals. We validate the code in a wide range of dark matter models by comparing results from MadDM v.2.0 to the existing tools and literature.

  1. Mapping monojet constraints onto Simplified Dark Matter Models

    E-Print Network [OSTI]

    Thomas Jacques; Karl Nordström

    2015-06-22

    The move towards simplified models for Run II of the LHC will allow for stronger and more robust constraints on the dark sector. However there already exists a wealth of Run I data which should not be ignored in the run-up to Run II. Here we reinterpret public constraints on generic beyond-standard-model cross sections to place new constraints on a simplified model. We make use of an ATLAS search in the monojet $+$ missing energy channel to constrain a representative simplified model with the dark matter coupling to an axial-vector $Z'$. We scan the entire parameter space of our chosen model to set the strongest current collider constraints on our model using the full 20.3 fb$^{-1}$ ATLAS 8 TeV dataset and provide predictions for constraints that can be set with 20 fb$^{-1}$ of 14 TeV data. Our technique can also be used for the interpretation of Run II data and provides a broad benchmark for comparing future constraints on simplified models.

  2. Stellar convective cores as dark matter probes

    E-Print Network [OSTI]

    Jordi Casanellas; Isa M. Brandão; Yveline Lebreton

    2015-05-06

    The recent detection of a convective core in a main-sequence solar-type star is used here to test particular models of dark matter (DM) particles, those with masses and scattering cross sections in the range of interest for the DM interpretation of the positive results in several DM direct detection experiments. If DM particles do not effectively self-annihilate after accumulating inside low-mass stars (e.g. in the asymmetric DM scenario) their conduction provides an efficient mechanism of energy transport in the stellar core. For main-sequence stars with masses between 1.1 and 1.3 Msun, this mechanism may lead to the suppression of the inner convective region expected to be present in standard stellar evolution theory. The asteroseismic analysis of the acoustic oscillations of a star can prove the presence/absence of such a convective core, as it was demonstrated for the first time with the Kepler field main-sequence solar-like pulsator, KIC 2009505. Studying this star we found that the asymmetric DM interpretation of the results in the CoGeNT experiment is incompatible with the confirmed presence of a small convective core in KIC 2009505.

  3. Dark Matter Admixed Type Ia Supernovae

    E-Print Network [OSTI]

    Leung, S -C; Lin, L -M

    2015-01-01

    We perform two-dimensional hydrodynamic simulations for the thermonuclear explosion of Chandrasekhar-mass white dwarfs with dark matter (DM) cores in Newtonian gravity. We include a 19-isotope nuclear reaction network and make use of the pure turbulent deflagration model as the explosion mechanism in our simulations. Our numerical results show that the general properties of the explosion depend quite sensitively on the mass of the DM core M$_{{\\rm DM}}$: a larger M$_{{\\rm DM}}$ generally leads to a weaker explosion and a lower mass of synthesized iron-peaked elements. In particular, the total mass of $^{56}$Ni produced can drop from about 0.3 to 0.03 $M_{\\odot}$ as M$_{{\\rm DM}}$ increases from 0.01 to 0.03 $M_{\\odot}$. We have also constructed the bolometric light curves obtained from our simulations and found that our results match well with the observational data of sub-luminous Type-Ia supernovae.

  4. A fluid mechanical explanation of dark matter

    E-Print Network [OSTI]

    Gibson, C H

    1999-01-01

    Matter in the universe has become ``dark'' or ``missing'' through misconceptions about the fluid mechanics of gravitational structure formation. Gravitational condensation occurs on non-acoustic density nuclei at the largest Schwarz length scale L_{ST}, L_{SV}, L_{SM}, L_{SD} permitted by turbulence, viscous, or magnetic forces, or by the fluid diffusivity. Non-baryonic fluids have diffusivities larger (by factors of trillions or more) than baryonic (ordinary) fluids, and cannot condense to nucleate baryonic galaxy formation as is usually assumed. Baryonic fluids begin to condense in the plasma epoch at about 13,000 years after the big bang to form proto-superclusters, and form proto-galaxies by 300,000 years when the cooling plasma becomes neutral gas. Condensation occurs at small planetary masses to form ``primordial fog particles'' from nearly all of the primordial gas by the new theory, Gibson (1996), supporting the Schild (1996) conclusion from quasar Q0957+651A,B microlensing observations that the mass ...

  5. Theory and observations of galactic dark matter

    E-Print Network [OSTI]

    Carl H. Gibson; Rudolph E. Schild

    1999-04-26

    Sir James Jeans's (1902 and 1929) linear, acoustic, theory of gravitational instability gives vast errors for the structure formation of the early universe. Gibson's (1996) nonlinear theory shows that nonacoustic density extrema produced by turbulence are gravitationally unstable at turbulent, viscous, or diffusive Schwarz scales L_ST, L_SV, L_SD, independent of Jeans's acoustic scale L_J. Structure formation began with decelerations of 10^46 kg protosuperclusters in the hot plasma epoch, 13,000 years after the Big Bang, when L_SV decreased to the Hubble (horizon) scale L_H equiv ct, where c is light speed and t is time, giving 10^42 kg protogalaxies just before the cooled plasma formed neutral H-He gas at 300,000 years. In 10^3 years this primordial gas condensed to 10^23 - 10^25 kg L_SV - L_ST scale objects, termed ``primordial fog particles'' (PFPs). Schild (1996) suggested from continuous microlensing of quasar Q0957 + 561 A,B that the mass of the 10^42 kg lens galaxy is dominated by 10^23 - 10^25 kg ``rogue planets ... likely to be the missing mass''. A microlensing event seen at three observatories confirms Schild's (1996) claims, and supports Gibson's (1996) prediction that PFPs comprise most of the dark matter at galactic scales.

  6. New Dark Matter Detector using Nanoscale Explosives

    E-Print Network [OSTI]

    Lopez, Alejandro; Freese, Katherine; Kurdak, Cagliyan; Tarle, Gregory

    2014-01-01

    We present nanoscale explosives as a novel type of dark matter detector and study the ignition properties. When a Weakly Interacting Massive Particle WIMP from the Galactic Halo elastically scatters off of a nucleus in the detector, the small amount of energy deposited can trigger an explosion. For specificity, this paper focuses on a type of two-component explosive known as a nanothermite, consisting of a metal and an oxide in close proximity. When the two components interact they undergo a rapid exothermic reaction --- an explosion. As a specific example, we consider metal nanoparticles of 5 nm radius embedded in an oxide. One cell contains more than a few million nanoparticles, and a large number of cells adds up to a total of 1 kg detector mass. A WIMP interacts with a metal nucleus of the nanoparticles, depositing enough energy to initiate a reaction at the interface between the two layers. When one nanoparticle explodes it initiates a chain reaction throughout the cell. A number of possible thermite mat...

  7. A search for Higgs-portal dark matter and new phenomena with monojet signatures in collisions at ? = 8 TeV

    E-Print Network [OSTI]

    AUTHOR|(SzGeCERN)708483

    A search for new phenomena in final states with one or more energetic jets and large missing transverse momentum is presented. An integrated luminosity of 20 fb^1 is collected from ? = 8 TeV collisions at the LHC with the ATLAS detector during 2012 operations. Standard Model backgrounds and systematics uncertainties are estimated using a maximum likelihood procedure. The number of events passing this selection criteria is in good agreement with Standard Model expectations. These events are then divided up into three orthogonal signal regions based on the outputs of two Random Forest classifiers trained to classify invisible decays of the Higgs boson produced through the vector boson fusion and Higgs-strahlung production modes. These results are then interpreted in terms of three different Higgs-portal models and translated into upper limits on WIMP-nucleon cross-sections for comparison with direct detection experiments.

  8. Galactic propagation of positrons from particle dark-matter annihilation

    E-Print Network [OSTI]

    I. V. Moskalenko; A. W. Strong

    1999-06-14

    We have made a calculation of the propagation of positrons from dark-matter particle annihilation in the Galactic halo for different models of the dark matter halo distribution using our 3D code. We show that the Green's functions are not very sensitive to the dark matter distribution for the same local dark matter energy density. We compare our predictions with computed cosmic ray positron spectra ("background") for the "conventional" cosmic-ray nucleon spectrum which matches the local measurements, and a modified spectrum which respects the limits imposed by measurements of diffuse Galactic gamma-rays, antiprotons, and positrons. We conclude that significant detection of a dark matter signal requires favourable conditions and precise measurements unless the dark matter is clumpy which would produce a stronger signal. Although our conclusion qualitatively agrees with that of previous authors, it is based on a more realistic model of particle propagation and thus reduces the scope for future speculations. Reliable background evaluation requires new accurate positron measurements and further developments in modelling production and propagation of cosmic ray species in the Galaxy.

  9. Nonstandard Yukawa Couplings and Higgs Portal Dark Matter

    E-Print Network [OSTI]

    Fady Bishara; Joachim Brod; Patipan Uttayarat; Jure Zupan

    2015-05-15

    We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross section, on the other hand, is subleading unless the dark matter is very light -- a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model, the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. Finally, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.

  10. Dark Matter with Topological Defects in the Inert Doublet Model

    E-Print Network [OSTI]

    Mark Hindmarsh; Russell Kirk; Jose Miguel No; Stephen M. West

    2015-07-29

    We examine the production of dark matter by decaying topological defects in the high mass region $m_{\\mathrm{DM}} \\gg m_W$ of the Inert Doublet Model, extended with an extra U(1) gauge symmetry. The density of dark matter states (the neutral Higgs states of the inert doublet) is determined by the interplay of the freeze-out mechanism and the additional production of dark matter states from the decays of topological defects, in this case cosmic strings. These decays increase the predicted relic abundance compared to the standard freeze-out only case, and as a consequence the viable parameter space of the Inert Doublet Model can be widened substantially. In particular, for a given dark matter annihilation rate lower dark matter masses become viable. We investigate the allowed mass range taking into account constraints on the energy injection rate from the diffuse $\\gamma$-ray background and Big Bang Nucleosynthesis, together with constraints on the dark matter properties coming from direct and indirect detection limits. For the Inert Doublet Model high-mass region, an inert Higgs mass as low as $\\sim 200$ GeV is permitted. There is also an upper limit on string mass per unit length, and hence the symmetry breaking scale, from the relic abundance in this scenario. Depending on assumptions made about the string decays, the limits are in the range $10^{12}$ GeV to $10^{13}$ GeV.

  11. Dark matter-radiation interactions: the impact on dark matter haloes

    E-Print Network [OSTI]

    J. A. Schewtschenko; R. J. Wilkinson; C. M. Baugh; C. Boehm; S. Pascoli

    2015-02-27

    Interactions between dark matter (DM) and radiation (photons or neutrinos) in the early Universe suppress density fluctuations on small mass scales. Here we perform a thorough analysis of structure formation in the fully non-linear regime using N-body simulations for models with DM-radiation interactions and compare the results to a traditional calculation in which DM only interacts gravitationally. Significant differences arise due to the presence of interactions, in terms of the number of low-mass DM haloes and their properties, such as their spin and density profile. These differences are clearly seen even for haloes more massive than the scale on which density fluctuations are suppressed. We also show that semi-analytical descriptions of the matter distribution in the non-linear regime fail to reproduce our numerical results, emphasizing the challenge of predicting structure formation in models with physics beyond collisionless DM.

  12. Boosted dark matter signals uplifted with self-interaction

    E-Print Network [OSTI]

    Kyoungchul Kong; Gopolang Mohlabeng; Jong-Chul Park

    2015-03-27

    We explore detection prospects of a non-standard dark sector in the context of boosted dark matter. We focus on a scenario with two dark matter particles of a large mass difference, where the heavier candidate is secluded and interacts with the standard model particles only at loops, escaping existing direct and indirect detection bounds. Yet its pair annihilation in the galactic center or in the Sun may produce boosted stable particles, which could be detected as visible Cherenkov light in large volume neutrino detectors. In such models with multiple candidates, self-interaction of dark matter particles is naturally utilized in the {\\it assisted freeze-out} mechanism and is corroborated by various cosmological studies such as N-body simulations of structure formation, observations of dwarf galaxies, and the small scale problem. We show that self-interaction of the secluded (heavier) dark matter greatly enhances the capture rate in the Sun and results in promising signals at current and future experiments. We perform a detailed analysis of the boosted dark matter events for Super-Kamiokande, Hyper-Kamiokande and PINGU, including notable effects such as evaporation due to self-interaction and energy loss in the Sun.

  13. Boosted dark matter signals uplifted with self-interaction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kong, Kyoungchul; Mohlabeng, Gopolang; Park, Jong -Chul

    2015-04-01

    We explore detection prospects of a non-standard dark sector in the context of boosted dark matter. We focus on a scenario with two dark matter particles of a large mass difference, where the heavier candidate is secluded and interacts with the standard model particles only at loops, escaping existing direct and indirect detection bounds. Yet its pair annihilation in the galactic center or in the Sun may produce boosted stable particles, which could be detected as visible Cherenkov light in large volume neutrino detectors. In such models with multiple candidates, self-interaction of dark matter particles is naturally utilized in themore »assisted freeze-out mechanism and is corroborated by various cosmological studies such as N-body simulations of structure formation, observations of dwarf galaxies, and the small scale problem. We show that self-interaction of the secluded (heavier) dark matter greatly enhances the capture rate in the Sun and results in promising signals at current and future experiments. We perform a detailed analysis of the boosted dark matter events for Super-Kamiokande, Hyper-Kamiokande and PINGU, including notable effects such as evaporation due to self-interaction and energy loss in the Sun.« less

  14. Dark matter, Mach's ether and the QCD vacuum

    E-Print Network [OSTI]

    Cohen-Tannoudji, Gilles

    2015-01-01

    Here is proposed the idea of linking the dark matter issue, (considered as a major problem of contemporary research in physics) with two other open theoretical questions, one, almost centenary about the existence of an unavoidable ether in general relativity agreeing with the Mach's principle, and one more recent about the properties of the quantum vacuum of the quantum field theory of strong interactions, QuantumChromodynamics (QCD). According to this idea, on the one hand, dark matter and dark energy that, according to the current standard model of cosmology represent about 95% of the universe content, can be considered as two distinct forms of the Mach's ether, and, on the other hand, dark matter, as a perfect fluid emerging from the QCD vacuum could be modeled as a Bose Einstein condensate.

  15. Is the Interacting Dark Matter Scenario an Alternative to Dark Energy ?

    E-Print Network [OSTI]

    Basilakos, S

    2008-01-01

    We study the global dynamics of the universe within the framework of the Interacting Dark Matter (IDM) scenario. Assuming that the dark matter obeys the collisional Boltzmann equation, we can derive analytical solutions of the global density evolution, which can accommodate an accelerated expansion, equivalent to either the {\\em quintessence} or the standard $\\Lambda$ models. We also find realistic solutions in which the present time is located after the inflection point.

  16. Searches for dark photons at the Mainz Microtron

    SciTech Connect (OSTI)

    Merkel, H.; Achenbach, P.; Gayoso, C. Ayerbe; Beranek, T.; Bernauer, J. C.; Böhm, R.; Correa, L.; Denig, A.; Distler, M. O.; Esser, A.; Gómez, M.; Kegel, S.; Kohl, Y.; Mihovilovi?, M.; Middleton, D. G.; Müller, U.; Nungesser, L.; Pochodzalla, J.; Rohrbeck, M.; Majos, S. Sánchez [Institut für Kernphysik, Johannes Gutenberg-Universität, D-55099 Mainz (Germany); and others

    2013-11-07

    The A1 Collaboration at the Mainz Microtron (MAMI) operates high resolution spectrometers at very high luminosities for fixed target electron scattering experiments. The setup is well suited for the search for dark photons in the mass range between 50 MeV and 300 MeV. In these experiments, a possible dark photon would appear as a sharp peak in the mass spectrum of di-lepton electro-production. In this presentation the potential of the setup is presented and the possibilities for future experiments for dark photon searches at MAMI are discussed.

  17. Dark matter, dark energy, and dark radiation coupled with a transversal interaction

    E-Print Network [OSTI]

    Luis P. Chimento; Martín G. Richarte

    2012-10-19

    We investigate a cosmological scenario with three interacting components that includes dark matter, dark energy, and radiation in the spatially flat Friedmann-Robertson-Walker universe. We introduce a 3-dimensional internal space, the interaction vector $\\mathbf{Q}=(Q_{x}, Q_{m}, Q_{r})$ satisfying the constraint plane $Q_{x}+ Q_{m}+ Q_{r}=0$, the barotropic index vector $ \\boldmath ${\\gamma}$=(\\ga_x,\\ga_m,\\ga_r)$ and select a transversal interaction vector $\\mathbf{Q_t}$ in a sense that $\\mathbf{Q_t}\\cdot \\boldmath ${\\gamma}$=0$. We exactly solve the source equation for a linear $\\mathbf{Q_t}$, that depends on the total energy density and its derivatives up to third order, and find all the component energy densities. We obtain a large set of interactions for which the source equation admits a power law solution and show its asymptotic stability by constructing the Lyapunov function. We apply the $\\chi^{2}$ method to the observational Hubble data for constraining the cosmic parameters, and analyze the amount of dark energy in the radiation era for the above linear $\\mathbf{Q_t}$. It turns to be that our model fulfills the severe bound of $\\Omega_{x}(z\\simeq 1100)<0.1$ and is consistent with the future constraints achievable by Planck and CMBPol experiments.

  18. Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope

    SciTech Connect (OSTI)

    Ackermann, M.; Ajello, M.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Albert, A.; /Taiwan, Natl. Taiwan U. /Ohio State U.; Atwood, W.B.; /UC, Santa Cruz; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Bechtol, K.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; Blandford, R.D.; Bloom, E.D.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Bregeon, J.; /INFN, Pisa; Brigida, M.; /Bari Polytechnic /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Buehler, R.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Burnett, T.H.; /Washington U., Seattle; Buson, S.; /INFN, Padua /Padua U. /ICE, Bellaterra /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /INFN, Rome /Rome U. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Artep Inc. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /ASDC, Frascati /Perugia U. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Montpellier U. /Stockholm U. /Stockholm U., OKC /ASDC, Frascati /ASDC, Frascati /Udine U. /INFN, Trieste /Bari Polytechnic /INFN, Bari /Naval Research Lab, Wash., D.C. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Montpellier U. /Bari Polytechnic /INFN, Bari /Ecole Polytechnique /NASA, Goddard /Hiroshima U. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Bari Polytechnic /INFN, Bari /INFN, Bari /ASDC, Frascati /NASA, Goddard /INFN, Perugia /Perugia U. /Bari Polytechnic /INFN, Bari /Bologna Observ. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /DAPNIA, Saclay /Alabama U., Huntsville; /more authors..

    2012-09-14

    Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10{sup -26} cm{sup 3} s{sup -1} at 5 GeV to about 5 x 10{sup -23} cm{sup 3} s{sup -1} at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section ({approx}3 x 10{sup -26} cm{sup 3} s{sup -1} for a purely s-wave cross section), without assuming additional boost factors.

  19. Too massive neutron stars: The role of dark matter?

    E-Print Network [OSTI]

    Ang Li; Feng Huang; Ren-Xin Xu

    2012-08-18

    The maximum mass of a neutron star is generally determined by the equation of state of the star material. In this study, we take into account dark matter particles, assumed to behave like fermions with a free parameter to account for the interaction strength among the particles, as a possible constituent of neutron stars. We find dark matter inside the star would soften the equation of state more strongly than that of hyperons, and reduce largely the maximum mass of the star. However, the neutron star maximum mass is sensitive to the particle mass of dark matter, and a very high neutron star mass larger than 2 times solar mass could be achieved when the particle mass is small enough. Such kind of dark-matter- admixed neutron stars could explain the recent measurement of the Shapiro delay in the radio pulsar PSR J1614-2230, which yielded a neutron star mass of 2 times solar mass that may be hardly reached when hyperons are considered only, as in the case of the microscopic Brueckner theory. Furthermore, in this particular case, we point out that the dark matter around a neutron star should also contribute to the mass measurement due to its pure gravitational effect. However, our numerically calculation illustrates that such contribution could be safely ignored because of the usual diluted dark matter environment assumed. We conclude that a very high mass measurement of about 2 times solar mass requires a really stiff equation of state in neutron stars, and find a strong upper limit (<= 0.64 GeV) for the particle mass of non-self- annihilating dark matter based on the present model.

  20. Search for dark photons from supersymmetric hidden valleys

    E-Print Network [OSTI]

    D0 Collaboration; V. Abazov

    2009-06-02

    We search for a new light gauge boson, a dark photon, with the D0 experiment. In the model we consider, supersymmetric partners are pair produced and cascade to lightest neutralinos that can decay into the hidden sector state plus either a photon or a dark photon. The dark photon decays through its mixing with a photon into fermion pairs. We therefore investigate a previously unexplored final state that contains a photon, two spatially close leptons, and large missing transverse energy. We do not observe any evidence for dark photons and set a limit on their production.