National Library of Energy BETA

Sample records for dark matter particles

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Dark matter CMB constraints and likelihoods for poor particle physicists

    SciTech Connect (OSTI)

    Cline, James M.; Scott, Pat, E-mail: jcline@physics.mcgill.ca, E-mail: patscott@physics.mcgill.ca [Department of Physics, McGill University, 3600 rue University, Montréal, QC, H3A 2T8 (Canada)

    2013-03-01

    The cosmic microwave background provides constraints on the annihilation and decay of light dark matter at redshifts between 100 and 1000, the strength of which depends upon the fraction of energy ending up in the form of electrons and photons. The resulting constraints are usually presented for a limited selection of annihilation and decay channels. Here we provide constraints on the annihilation cross section and decay rate, at discrete values of the dark matter mass m{sub ?}, for all the annihilation and decay channels whose secondary spectra have been computed using PYTHIA in arXiv:1012.4515 (''PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection''), namely e, ?, ?, V ? e, V ? ?, V ? ?, u, d s, c, b, t, ?, g, W, Z and h. By interpolating in mass, these can be used to find the CMB constraints and likelihood functions from WMAP7 and Planck for a wide range of dark matter models, including those with annihilation or decay into a linear combination of different channels.

  10. 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...

  11. Model-independent analyses of dark-matter particle interactions

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

    Anand, Nikhil; Fitzpatrick, A. Liam; Haxton, W. C.

    2015-03-24

    A model-independent treatment of dark-matter particle elastic scattering has been developed, yielding the most general interaction for WIMP-nucleon low-energy scattering, and the resulting amplitude has been embedded into the nucleus, taking into account the selection rules imposed by parity and time-reversal. One finds that, in contrast to the usual spin-independent/spin-dependent (SI/SD) formulation, the resulting cross section contains six independent nuclear response functions, three of which are associated with possible velocity-dependent interactions. We find that current experiments are four orders of magnitude more sensitive to derivative couplings than is apparent in the standard SI/SD treatment, which necessarily associated such interactions withmore »cross sections proportional to v2T ~ 10??, where vT is the WIMP velocity relative to the center of mass of the nuclear target.« less

  12. 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...

  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. Effect of low mass dark matter particles on the Sun

    E-Print Network [OSTI]

    Marco Taoso; Fabio Iocco; Georges Meynet; Gianfranco Bertone; Patrick Eggenberger

    2010-09-07

    We study the effect of dark matter (DM) particles in the Sun, focusing in particular on the possible reduction of the solar neutrinos flux due to the energy carried away by DM particles from the innermost regions of the Sun, and to the consequent reduction of the temperature of the solar core. We find that in the very low-mass range between 4 and 10 GeV, recently advocated to explain the findings of the DAMA and CoGent experiments, the effects on neutrino fluxes are detectable only for DM models with very small, or vanishing, self-annihilation cross section, such as the so-called asymmetric DM models, and we study the combination of DM masses and Spin Dependent cross sections which can be excluded with current solar neutrino data. Finally, we revisit the recent claim that DM models with large self-interacting cross sections can lead to a modification of the position of the convective zone, alleviating or solving the solar composition problem. We show that when the `geometric' upper limit on the capture rate is correctly taken into account, the effects of DM are reduced by orders of magnitude, and the position of the convective zone remains unchanged.

  15. 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.

  16. Two loop neutrino model and dark matter particles with global B?L symmetry

    SciTech Connect (OSTI)

    Baek, Seungwon; Okada, Hiroshi; Toma, Takashi E-mail: hokada@kias.re.kr

    2014-06-01

    We study a two loop induced seesaw model with global U(1){sub B?L} symmetry, in which we consider two component dark matter particles. The dark matter properties are investigated together with some phenomenological constraints such as electroweak precision test, neutrino masses and mixing and lepton flavor violation. In particular, the mixing angle between the Standard Model like Higgs and an extra Higgs is extremely restricted by the direct detection experiment of dark matter. We also discuss the contribution of Goldstone boson to the effective number of neutrino species ?N{sub eff} ? 0.39 which has been reported by several experiments.

  17. 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.

  18. Scattering of nucleons on cold-dark-matter particles through photonic portal

    E-Print Network [OSTI]

    Wojciech Krolikowski

    2010-04-29

    In the model of hidden sector proposed recently, protons and neutrons scatter differently on cold-dark-matter particles. First, we summarize briefly our model based on a mechanism of "photonic portal" between hidden and Standard-Model sectors of the Universe. Then, we calculate in an elementary way the differential cross-sections for scattering of protons and neutrons on sterile Dirac fermions ("sterinos") playing the role of cold-dark-matter particles. They interact with nucleons through the photonic portal in a somewhat involved but natural manner. Due to this portal, the differential cross-section for protons displays a Coulomb-like forward singularity.

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. What is the spectrum of cold dark matter particles on Earth?

    E-Print Network [OSTI]

    Pierre Sikivie

    1996-06-24

    It is argued that the spectrum of cold dark matter particles on Earth has peaks in velocity space associated with particles falling onto the Galaxy for the first time and with particles which have fallen in and out of the Galaxy only a small number of times in the past. Estimates are given for the sizes and velocity magnitudes of the first few peaks. The estimates are based upon the secondary infall model of halo formation which has been generalized to include the effect of angular momentum.

  5. Dark matter formation at Schwarz scales: primordial fog particles and WIMP superhalos

    E-Print Network [OSTI]

    Carl H. Gibson

    1999-04-21

    Dark matter appears in two forms as a consequence of the fluid mechanics of self-gravitational condensation. Condensation occurs primarily on non-acoustic nuclei rather than on the acoustic nuclei of the Jeans (1902) criterion, leading to a very different scenario for structure formation. Viscous forces at 10^12 s (30,000 y) after the big bang permit decelerations of 10^47 kg protosupercluster plasma masses, and 10^42 kg protogalaxy masses at 10^13 s (300,000 y). Then gas formed, and all the baryonic universe became a "primordial fog" of 10^23 kg particles at the viscous Schwarz scale: 100% dark matter. Some of these H-He objects have collected to form stars, but most persist as dark dwarfs in galaxy halos. They manifest themselves in quasar microlensing observations as "rogue planets", Schild (1996), "dark galaxies", Hawkins (1996), and as comets "brought out of cold storage", O'Dell and Handron (1996). Non-baryonic WIMP fluids are superviscous, with large viscous Schwarz scales, and condense slowly to form most of the dark matter of galaxy superclusterhalos and clusterhalos.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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 ...

  12. The Convergence of Particle-in-Cell Schemes for Cosmological Dark Matter Simulations

    E-Print Network [OSTI]

    Myers, Andrew; Van Straalen, Brian

    2015-01-01

    Particle methods are a ubiquitous tool for solving the Vlasov-Poisson equation in comoving coordinates, which is used to model the gravitational evolution of dark matter in an expanding universe. However, these methods are known to produce poor results on idealized test problems, particularly at late times, after the particle trajectories have crossed. To investigate this, we have performed a series of one- and two-dimensional "Zel'dovich Pancake" calculations using the popular Particle-in-Cell (PIC) method. We find that PIC can indeed converge on these problems provided the following modifications are made. The first modification is to regularize the singular initial distribution function by introducing a small but finite artificial velocity dispersion. This process is analogous to artificial viscosity in compressible gas dynamics, and, as with artificial viscosity, the amount of regularization can be tailored so that its effect outside of a well-defined region - in this case, the high-density caustics - is ...

  13. 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.

  14. 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.

  15. Is it possible to discover a dark matter particle with an accelerator?

    E-Print Network [OSTI]

    Vadim A. Bednyakov

    2015-06-28

    The paper contains description of the main properties of the galactic dark matter (DM) particles, available approaches for detection of DM, main features of direct DM detection, ways to estimate prospects for the DM detection, the first collider search for a DM candidate within an Effective Field Theory, complete review of ATLAS results of the DM candidate search with LHC RUN I, and less complete review of "exotic" dark particle searches with other accelerators and not only. From these considerations it follows that one is unable to prove, especially model-independently,a discovery of a DM particle with an accelerator, or collider. One can only obtain evidence on existence of a weakly interacting neutral particle, which could be, or could not be the DM candidate. The current LHC DM search program uses only the missing transverse energy signature. Non-observation of any excess above Standard Model expectations forces the LHC experiments to enter into the same fighting for the best exclusion curve, in which (almost) all direct and indirect DM search experiments permanently take place. But this fighting has very little (almost nothing) to do with a real possibility of discovering a DM particle. The true DM particles possess an exclusive galactic signature --- annual modulation of a signal, which is accessible today only for direct DM detection experiments. There is no way for it with a collider, or accelerator. Therefore to prove the DM nature of a collider-discovered candidate one must find the candidate in a direct DM experiment and demonstrate the galactic signature for the candidate. Furthermore, being observed, the DM particle must be implemented into a modern theoretical framework. The best candidate is the supersymmetry, which looks today inevitable for coherent interpretation of all available DM data.

  16. 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.

  17. 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 ...

  18. 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.

  19. PPPC 4 DM?: a Poor Particle Physicist Cookbook for Neutrinos from Dark Matter annihilations in the Sun

    SciTech Connect (OSTI)

    Baratella, Pietro; Cirelli, Marco; Hektor, Andi; Pata, Joosep; Piibeleht, Morten; Strumia, Alessandro E-mail: marco.cirelli@cea.fr E-mail: joosep.pata@cern.ch E-mail: alessandro.strumia@cern.ch

    2014-03-01

    We provide ingredients and recipes for computing neutrino signals of TeV-scale Dark Matter (DM) annihilations in the Sun. For each annihilation channel and DM mass we present the energy spectra of neutrinos at production, including: state-of-the-art energy losses of primary particles in solar matter, secondary neutrinos, electroweak radiation. We then present the spectra after propagation to the Earth, including (vacuum and matter) flavor oscillations and interactions in solar matter. We also provide a numerical computation of the capture rate of DM particles in the Sun. These results are available in numerical form.

  20. On the classical description of the recombination of dark matter particles with a Coulomb-like interaction

    E-Print Network [OSTI]

    Belotsky, K M; Kirillov, A A

    2015-01-01

    Cold dark matter (DM) scenario may be cured of several problems by involving self-interaction of dark matter. Viability of the models of long-range interacting DM crucially depends on the effectiveness of recombination of the DM particles, making thereby their interaction short-range. Usually in numeric calculations, recombination is described by cross section obtained on a feasible quantum level. However in a wide range of parameter values, a classical treatment, where the particles are bound due to dipole radiation, is applicable. The cross sections, obtained in both approaches, are very different and lead to diverse consequences. Classical cross section has a steeper dependence on relative velocity, what leads to the fact that, after decoupling of DM particles from thermal background of "dark photons" (carriers of DM long-range interaction), recombination process does not "freeze out", diminishing gradually density of unbound DM particles. Our simplified estimates show, that at the taken parameter values (...

  1. 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.

  2. 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...

  3. 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.

  4. Is the effect of the Sun's gravitational potential on dark matter particles observable?

    SciTech Connect (OSTI)

    Bozorgnia, Nassim; Schwetz, Thomas E-mail: schwetz@fysik.su.se

    2014-08-01

    We consider the effect of the Sun's gravitational potential on the local phase space distribution of dark matter particles, focusing on its implication for the annual modulation signal in direct detection experiments. We perform a fit to the modulation signal observed in DAMA/LIBRA and show that the allowed region shrinks if Solar gravitational focusing (GF) is included compared to the one without GF. Furthermore, we consider a possible signal in a generic future direct detection experiment, irrespective of the DAMA/LIBRA signal. Even for scattering cross sections close to the current bound and a large exposure of a xenon target with 270 ton yr it will be hard to establish the presence of GF from data. In the region of dark matter masses below 40 GeV an annual modulation signal can be established for our assumed experimental setup, however GF is negligible for low masses. In the high mass region, where GF is more important, the significance of annual modulation itself is very low. We obtain similar results for lighter targets such as Ge and Ar. We comment also on inelastic scattering, noting that GF becomes somewhat more important for exothermic scattering compared to the elastic case.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Dark Matter Particle Spectroscopy at the LHC: Generalizing M(T2) to Asymmetric Event Topologies

    SciTech Connect (OSTI)

    Konar, Partha; Kong, Kyoungchul; Matchev, Konstantin T.; Park, Myeonghun; /Florida U.

    2012-04-03

    We consider SUSY-like missing energy events at hadron colliders and critically examine the common assumption that the missing energy is the result of two identical missing particles. In order to experimentally test this hypothesis, we generalize the subsystem M{sub T2} variable to the case of asymmetric event topologies, where the two SUSY decay chains terminate in different 'children' particles. In this more general approach, the endpoint M{sub T2(max)} of the M{sub T2} distribution now gives the mass {tilde M}p({tilde M}{sub c}{sup (a)}, {tilde M}{sub c}{sup (b)}) of the parent particles as a function of two input children masses {tilde M}{sub c}{sup (a)} and {tilde M}{sub c}{sup (b)}. We propose two methods for an independent determination of the individual children masses M{sub c}{sup (a)} and M{sub c}{sup (b)}. First, in the presence of upstream transverse momentum PUTM the corresponding function {tilde M}p({tilde M}{sub c}{sup (a)}, {tilde M}{sub c}{sup (b)}, P{sub UTM}) is independent of P{sub UTM} at precisely the right values of the children masses. Second, the previously discussed MT2 'kink' is now generalized to a 'ridge' on the 2-dimensional surface {tilde M}p({tilde M}{sub c}{sup (a)}, {tilde M}{sub c}{sup (b)}). As we show in several examples, quite often there is a special point along that ridge which marks the true values of the children masses. Our results allow collider experiments to probe a multi-component dark matter sector directly and without any theoretical prejudice.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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 ($\\sigma_8$).

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Local Group dSph radio survey with ATCA (III): constraints on particle dark matter

    SciTech Connect (OSTI)

    Regis, Marco [Dipartimento di Fisica, Università di Torino, via P. Giuria 1, I-10125 Torino (Italy); Colafrancesco, Sergio [School of Physics, University of the Witwatersrand, Johannesburg (South Africa); Profumo, Stefano [Department of Physics, University of California, 1156 High St., Santa Cruz, CA 95064 (United States); De Blok, W.J.G. [Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA Dwingeloo (Netherlands); Massardi, Marcella [INAF—Istituto di Radioastronomia, Via Gobetti 101, I-40129, Bologna (Italy); Richter, Laura, E-mail: regis@to.infn.it, E-mail: sergio.colafrancesco@wits.ac.za, E-mail: profumo@ucsc.edu, E-mail: blok@astron.nl, E-mail: massardi@ira.inaf.it, E-mail: laura@ska.ac.za [SKA South Africa, 3rd Floor, The Park, Park Road, Pinelands, 7405 (South Africa)

    2014-10-01

    We performed a deep search for radio synchrotron emissions induced by weakly interacting massive particles (WIMPs) annihilation or decay in six dwarf spheroidal (dSph) galaxies of the Local Group. Observations were conducted with the Australia Telescope Compact Array (ATCA) at 16 cm wavelength, with an rms sensitivity better than 0.05 mJy/beam in each field. In this work, we first discuss the uncertainties associated with the modeling of the expected signal, such as the shape of the dark matter (DM) profile and the dSph magnetic properties. We then investigate the possibility that point-sources detected in the proximity of the dSph optical center might be due to the emission from a DM cuspy profile. No evidence for an extended emission over a size of few arcmin (which is the DM halo size) has been detected. We present the associated bounds on the WIMP parameter space for different annihilation/decay final states and for different astrophysical assumptions. If the confinement of electrons and positrons in the dSph is such that the majority of their power is radiated within the dSph region, we obtain constraints on the WIMP annihilation rate which are well below the thermal value for masses up to few TeV. On the other hand, for conservative assumptions on the dSph magnetic properties, the bounds can be dramatically relaxed. We show however that, within the next 10 years and regardless of the astrophysical assumptions, it will be possible to progressively close in on the full parameter space of WIMPs by searching for radio signals in dSphs with SKA and its precursors.

  4. 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.

  5. 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 ...

  6. 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, ...

  7. 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...

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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. ...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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

  18. 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.

  19. 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.

  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. 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.

  2. 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.

  3. 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)

  4. 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)

  5. 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.

  6. 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.

  7. 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).

  8. 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.

  9. 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.

  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. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

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

    E-Print Network [OSTI]

    Arruda, Luísa; Pereira, Rui

    2007-01-01

    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 topi...

  18. Light dark matter candidates in intense laser pulses I: paraphotons and fermionic minicharged particles

    E-Print Network [OSTI]

    Selym Villalba-Chávez; Carsten Müller

    2014-12-15

    Polarimetric experiments driven by the strong field of a circularly polarized laser wave can become a powerful tool to limit the parameter space of not yet detected hidden-photons and minicharged particles associated with extra U(1) gauge symmetries. We show how the absorption and dispersion of probe electromagnetic waves in the vacuum polarized by such a background are modified due to the coupling between the visible U(1)-gauge sector and these hypothetical degrees of freedom. The results of this analysis reveal that the regime close to the two-photon reaction threshold can be a sensititive probe of these hidden particles. Parameters of modern laser systems are used to estimate the constraints on the corresponding coupling constants in regions where experiments driven by dipole magnets are less constricted. The role played by a paraphoton field is analyzed via a comparison with a model in which the existence of minicharges is assumed only. For both scenarios is found that the most stringent exclusion limit occurs at the lowest threshold mass; this one being determined by a certain combination of the field frequencies and dictated by energy momentum balance of the photo-production of a pair of minicharged particles. The dependencies of the observables on the laser attributes as well as on the unknown particle parameters are also analyzed.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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)

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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).

  15. 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

  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 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.

  18. 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.

  19. 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.

  20. 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.

  1. A model of the directional sensitivity of low-pressure CF? dark matter detectors

    E-Print Network [OSTI]

    Deaconu, Cosmin ?tefan

    2015-01-01

    Identification of the composition of dark matter is one of the major unsolved puzzles in modern physics. Detectors with sensitivity to the direction of certain classes of dark matter particles have potentially very powerful ...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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 ...

  15. 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.

  16. 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

  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. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. Gamma-ray and Radio Constraints of High Positron Rate Dark Matter Models Annihilating into New Light Particles

    E-Print Network [OSTI]

    Lars Bergstrom; Gianfranco Bertone; Torsten Bringmann; Joakim Edsjo; Marco Taoso

    2009-06-04

    The possibility of explaining the positron and electron excess recently found by the PAMELA and ATIC collaborations in terms of dark matter (DM) annihilation has attracted considerable attention. Models surviving bounds from, e.g, antiproton production generally fall into two classes, where either DM annihilates directly with a large branching fraction into light leptons, or, as in the recent models of Arkani-Hamed et al., and of Nomura and Thaler, the annihilation gives low-mass (pseudo)scalars or vectors $\\phi$ which then decay into $\\mu^+\\mu^-$ or $e^+e^-$. While the constraints on the first kind of models have recently been treated by several authors, we study here specifically models of the second type which rely on an efficient Sommerfeld enhancement in order to obtain the necessary boost in the annihilation cross section. We compute the photon flux generated by QED radiative corrections to the decay of $\\phi$ and show that this indeed gives a rather spectacular broad peak in $E^2d\\sigma/dE$, that for these extreme values of the cross section violate gamma-ray observations of the Galactic center for DM density profiles steeper than that of Navarro, Frenk and White. The most stringent constraint comes from the comparison of the predicted synchrotron radiation in the central part of the Galaxy with radio observations of Sgr A*. For the most commonly adopted DM profiles, the models that provide a good fit to the PAMELA and ATIC data are ruled out, unless there are physical processes that boost the local anti-matter fluxes more than one order of magnitude, while not affecting the gamma-ray or radio fluxes.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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 ...

  17. 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.

  18. Gamma-ray and radio constraints of high positron rate dark matter models annihilating into new light particles

    SciTech Connect (OSTI)

    Bergstroem, Lars; Bringmann, Torsten; Edsjoe, Joakim; Bertone, Gianfranco; Taoso, Marco

    2009-04-15

    The possibility of explaining the positron and electron excess recently found by the PAMELA and ATIC Collaborations in terms of dark matter (DM) annihilation has attracted considerable attention. Models surviving bounds from, e.g., antiproton production generally fall into two classes, where either DM annihilates directly with a large branching fraction into light leptons, or, as in the recent models of Arkani-Hamed et al., and of Nomura and Thaler, the annihilation gives low-mass (pseudo)scalars or vectors {phi} which then decay into {mu}{sup +}{mu}{sup -} or e{sup +}e{sup -}. While the constraints on the first kind of models have recently been treated by several authors, we study here specifically models of the second type which rely on an efficient Sommerfeld enhancement in order to obtain the necessary boost in the annihilation cross section. We compute the photon flux generated by QED radiative corrections to the decay of {phi} and show that this indeed gives a rather spectacular broad peak in E{sup 2}d{sigma}/dE, which for these extreme values of the cross section violates gamma-ray observations of the Galactic center for DM density profiles steeper than that of Navarro, Frenk and White. The most stringent constraint comes from the comparison of the predicted synchrotron radiation in the central part of the Galaxy with radio observations of Sgr A*. For the most commonly adopted DM profiles, the models that provide a good fit to the PAMELA and ATIC data are ruled out, unless there are physical processes that boost the local antimatter fluxes more than 1 order of magnitude, while not affecting the gamma-ray or radio fluxes.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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 ...

  8. 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.

  9. 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 ;...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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 ...

  17. 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.

  18. 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...

  19. 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.

  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. 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.

  2. Dark radiation from particle decay: cosmological constraints and opportunities

    SciTech Connect (OSTI)

    Hasenkamp, Jasper; Kersten, Jörn, E-mail: Jasper.Hasenkamp@desy.de, E-mail: Joern.Kersten@desy.de [II. Institute for Theoretical Physics, University of Hamburg, 22761 Hamburg (Germany)

    2013-08-01

    We study particle decay as the origin of dark radiation. After elaborating general properties and useful parametrisations we provide model-independent and easy-to-use constraints from nucleosynthesis, the cosmic microwave background and structure formation. Bounds on branching ratios and mass hierarchies depend in a unique way on the time of decay. We demonstrate their power to exclude well-motivated scenarios taking the example of the lightest ordinary sparticle decaying into the gravitino. We point out signatures and opportunities in cosmological observations and structure formation. For example, if there are two dark decay modes, dark radiation and the observed dark matter with adjustable free-streaming can originate from the same decaying particle, solving small-scale problems of structure formation. Hot dark matter mimicking a neutrino mass scale as deduced from cosmological observations can arise and possibly be distinguished after a discovery. Our results can be used as a guideline for model building.

  3. 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.

  4. 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.

  5. Photonic portal to the sterile world of cold dark matter

    E-Print Network [OSTI]

    Wojciech Krolikowski

    2007-12-18

    We assume that the cold dark matter consists of spin-1/2 and spin-0 particles described by a bispinor field \\psi and a scalar field \\phi, sterile from all Standard Model charges (in contrast, neutralinos, supersymmetric candidates for cold dark matter, are not sterile from weak Standard Model charges). We propose, however, that such a sterile world can contact with our Standard Model world not only through gravity but also through a portal provided by photons coupled to sterile particles by means of two very weak effective interactions -(f/M^2)\\phi F^{\\mu\

  6. DarkSUSY - A numerical package for supersymmetric dark matter calculations

    E-Print Network [OSTI]

    Paolo Gondolo; Joakim Edsjo; Piero Ullio; Lars Bergstrom; Mia Schelke; Edward A. Baltz

    2002-11-12

    The question of the nature of dark matter in the Universe remains one of the most outstanding unsolved problems in basic science. One of the best motivated particle physics candidates is the lightest supersymmetric particle, assumed to be the lightest neutralino. We here describe DarkSUSY, an advanced numerical FORTRAN package for supersymmetric dark matter calculations. With DarkSUSY one can: (i) compute masses and compositions of various supersymmetric particles; (ii) compute the relic density of the lightest neutralino, using accurate methods which include the effects of resonances, pair production thresholds and coannihilations; (iii) check accelerator bounds to identify allowed supersymmetric models; and (iv) obtain neutralino detection rates for a variety of detection methods, including direct detection and indirect detection through antiprotons, gamma-rays and positrons from the Galactic halo or neutrinos from the center of the Earth or the Sun.

  7. 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.

  8. Boosted Dark Matter Signals Uplifted with Self-Interaction

    E-Print Network [OSTI]

    Kong, Kyoungchul; Park, Jong-Chul

    2015-01-01

    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 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...

  9. New primordial $^4\\text{He}$ constraints on inelastic macro dark matter

    E-Print Network [OSTI]

    Jacobs, David M; Mafune, Mpho; Manikumar, Samyukta; Weltman, Amanda

    2015-01-01

    At present, the best model for the evolution of the cosmos requires that dark matter makes up approximately 25% of the energy content of the Universe. Most approaches to explain the microscopic nature of dark matter, to date, have assumed its composition to be of intrinsically weakly-interacting particles; however, this need not be the case to have consistency with all extant observations. Given decades of no conclusive evidence to support any dark matter candidate so far, there is strong motivation to consider alternatives to the standard particle scenario. One such example is macro dark matter, a class of candidates that could interact quite strongly with the particles of the Standard Model, have large masses and physical sizes, yet behave as dark matter. Here we reconsider the effect of inelastically interacting macro dark matter on the abundance of primordially produced $^4\\text{He}$, revising older constraints by both revisiting the phenomenology and taking into account recent improved measurements of th...

  10. First results from a 20-liter prototype dark matter detector with directional sensitivity

    E-Print Network [OSTI]

    Lopez, Jeremy Paul

    2014-01-01

    Astronomical and cosmological evidence suggests that 27% of the energy content of the universe is in the form of non-baryonic matter referred to as "dark matter." Weakly interacting massive particles have long been considered ...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  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. 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. 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. Origin of Delta N_eff as a Result of an Interaction between Dark Radiation and Dark Matter

    E-Print Network [OSTI]

    Ole Eggers Bjaelde; Subinoy Das; Adam Moss

    2012-09-28

    Results from the Wilkinson Microwave Anisotropy Probe (WMAP), Atacama Cosmology Telescope (ACT) and recently from the South Pole Telescope (SPT) have indicated the possible existence of an extra radiation component in addition to the well known three neutrino species predicted by the Standard Model of particle physics. In this paper, we explore the possibility of the apparent extra dark radiation being linked directly to the physics of cold dark matter (CDM). In particular, we consider a generic scenario where dark radiation, as a result of an interaction, is produced directly by a fraction of the dark matter density effectively decaying into dark radiation. At an early epoch when the dark matter density is negligible, as an obvious consequence, the density of dark radiation is also very small. As the Universe approaches matter radiation equality, the dark matter density starts to dominate thereby increasing the content of dark radiation and changing the expansion rate of the Universe. As this increase in dark radiation content happens naturally after Big Bang Nucleosynthesis (BBN), it can relax the possible tension with lower values of radiation degrees of freedom measured from light element abundances compared to that of the CMB. We numerically confront this scenario with WMAP+ACT and WMAP+SPT data and derive an upper limit on the allowed fraction of dark matter decaying into dark radiation.

  1. 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

  2. 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.

  3. 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...

  4. 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

  5. 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.

  6. 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.

  7. 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...

  8. Excluding the light dark matter window of a 331 model using LHC and direct dark matter detection data

    SciTech Connect (OSTI)

    Cogollo, D.; Gonzalez-Morales, Alma X.; Queiroz, Farinaldo S.; Teles, P. Rebello E-mail: alxogonz@ucsc.edu E-mail: patricia.rebello.teles@cern.ch

    2014-11-01

    We sift the impact of the recent Higgs precise measurements, and recent dark matter direct detection results, on the dark sector of an electroweak extension of the Standard Model that has a complex scalar as dark matter. We find that in this model the Higgs decays with a large branching ratio into dark matter particles, and charged scalars when these are kinematically available, for any coupling strength differently from the so called Higgs portal. Moreover, we compute the abundance and spin-independent WIMP-nucleon scattering cross section, which are driven by the Higgs and Z{sup '} boson processes. We decisively exclude the 1–500 GeV dark matter window and find the most stringent lower bound in the literature on the scale of symmetry breaking of the model namely 10 TeV, after applying the LUX-2013 limit. Interestingly, the projected XENON1T constraint will be able to rule out the entire 1 GeV–1000 GeV dark matter mass range. Lastly, for completeness, we compute the charged scalar production cross section at the LHC and comment on the possibility of detection at current and future LHC runnings.

  9. Dark Matter Hawking Radiation? Dark Spinors Tunnelling in String Theory Black Holes

    E-Print Network [OSTI]

    Cavalcanti, R T

    2015-01-01

    The Hawking radiation spectrum of Kerr-Sen axion-dilaton black holes is derived, in the context of dark spinors tunnelling across the horizon. Since a black hole has a well defined temperature, it should radiate in principle all the standard model particles, similar to a black body at that temperature. We investigate the tunnelling of mass dimension one spin-1/2 dark fermions, that are beyond the standard model and are prime candidates to the dark matter. Their interactions with the standard model matter and gauge fields are suppressed by at least one power of unification scale, being restricted just to the Higgs field and to the graviton likewise. The tunnelling method for the emission and absorption of mass dimension one particles across the event horizon of Kerr-Sen axion-dilaton black holes is shown here to provide further evidence for the universality of black hole radiation, further encompassing particles beyond the standard model.

  10. Dark Matter Hawking Radiation? Dark Spinors Tunnelling in String Theory Black Holes

    E-Print Network [OSTI]

    R. T. Cavalcanti; Roldao da Rocha

    2015-07-14

    The Hawking radiation spectrum of Kerr-Sen axion-dilaton black holes is derived, in the context of dark spinors tunnelling across the horizon. Since a black hole has a well defined temperature, it should radiate in principle all the standard model particles, similar to a black body at that temperature. We investigate the tunnelling of mass dimension one spin-1/2 dark fermions, that are beyond the standard model and are prime candidates to the dark matter. Their interactions with the standard model matter and gauge fields are suppressed by at least one power of unification scale, being restricted just to the Higgs field and to the graviton likewise. The tunnelling method for the emission and absorption of mass dimension one particles across the event horizon of Kerr-Sen axion-dilaton black holes is shown here to provide further evidence for the universality of black hole radiation, further encompassing particles beyond the standard model.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. A new test of the light dark matter hypothesis

    E-Print Network [OSTI]

    Celine Boehm; Joseph Silk

    2007-08-21

    Detection of a surprisingly high flux of positron annihilation radiation from the inner galaxy has motivated the proposal that dark matter is made of weakly interacting light particles (possibly as light as the electron). This scenario is extremely hard to test in current high energy physics experiments. Here, however, we demonstrate that the current value of the electron anomalous magnetic moment already has the required precision to unambiguously test the light dark matter hypothesis. If confirmed, the implications for astrophysics are far-reaching.

  16. 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.

  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. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Enhancement of Majorana dark matter annihilation through Higgs bremsstrahlung

    SciTech Connect (OSTI)

    Luo, Feng; You, Tevong E-mail: tevong.you@kcl.ac.uk

    2013-12-01

    For Majorana dark matter, gauge boson bremsstrahlung plays an important role in enhancing an otherwise helicity-suppressed s-wave annihilation cross-section. This is well known for processes involving a radiated photon or gluon together with a Standard Model fermion-antifermion pair, and the case of massive electroweak gauge bosons has also recently been studied. Here we show that internal Higgs bremsstrahlung also lifts helicity suppression and could be the dominant contribution to the annihilation rate in the late Universe for dark matter masses below ? 1 TeV. Using a toy model of leptophilic dark matter, we calculate the annihilation cross-section into a lepton-antilepton pair with a Higgs boson and investigate the energy spectra of the final stable particles at the annihilation point.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Identifying Dark Matter Burners in the Galactic center

    E-Print Network [OSTI]

    Igor V. Moskalenko; Lawrence L. Wai

    2007-04-11

    If the supermassive black hole (SMBH) at the center of our Galaxy grew adiabatically, then a dense "spike" of dark matter is expected to have formed around it. Assuming that dark matter is composed primarily of weakly interacting massive particles (WIMPs), a star orbiting close enough to the SMBH can capture 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, i.e. "WIMP burners", in the vicinity of an adiabatically grown SMBH. We find that the most efficient WIMP burners are stars with degenerate electron cores, e.g. white dwarfs (WD) or degenerate cores with envelopes. If found, such stars would provide evidence for the existence of particle dark matter and could possibly be used to establish its density profile. In our previous paper we computed the luminosity from WIMP burning for a range of dark matter spike density profiles, degenerate core masses, and distances from the SMBH. Here we compare our results with the observed stars closest to the Galactic center and find that they could be consistent with WIMP burners in the form of degenerate cores with envelopes. We also cross-check the WIMP burner hypothesis with the EGRET observed flux of gamma-rays from the Galactic center, which imposes a constraint on the dark matter spike density profile and annihilation cross-section. We find that the EGRET data is consistent with the WIMP burner hypothesis. New high precision measurements by GLAST will confirm or set stringent limits on a dark matter spike at the Galactic center, which will in turn support or set stringent limits on the existence of WIMP burners at the Galactic center.

  10. 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.

  11. 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.

  12. On the Oscillation of Neutrinos Produced by the Annihilation of Dark Matter inside the Sun

    E-Print Network [OSTI]

    Arman Esmaili; Yasaman Farzan

    2010-06-14

    The annihilation of dark matter particles captured by the Sun can lead to a neutrino flux observable in neutrino detectors. Considering the fact that these dark matter particles are non-relativistic, if a pair of dark matter annihilates to a neutrino pair, the spectrum of neutrinos will be monochromatic. We show that in this case, even after averaging over production point inside the Sun, the oscillatory terms of the oscillation probability do not average to zero. This leads to interesting observable features in the annual variation of the number of muon track events. We show that smearing of the spectrum due to thermal distribution of dark matter inside the Sun is too small to wash out this variation. We point out the possibility of studying the initial flavor composition of neutrinos produced by the annihilation of dark matter particles via measuring the annual variation of the number of muon-track events in neutrino telescopes.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Global fits of the dark matter-nucleon effective interactions

    SciTech Connect (OSTI)

    Catena, Riccardo; Gondolo, Paolo E-mail: paolo.gondolo@utah.edu

    2014-09-01

    The effective theory of isoscalar dark matter-nucleon interactions mediated by heavy spin-one or spin-zero particles depends on 10 coupling constants besides the dark matter particle mass. Here we compare this 11-dimensional effective theory to current observations in a comprehensive statistical analysis of several direct detection experiments, including the recent LUX, SuperCDMS and CDMSlite results. From a multidimensional scan with about 3 million likelihood evaluations, we extract the marginalized posterior probability density functions (a Bayesian approach) and the profile likelihoods (a frequentist approach), as well as the associated credible regions and confidence levels, for each coupling constant vs dark matter mass and for each pair of coupling constants. We compare the Bayesian and frequentist approach in the light of the currently limited amount of data. We find that current direct detection data contain sufficient information to simultaneously constrain not only the familiar spin-independent and spin-dependent interactions, but also the remaining velocity and momentum dependent couplings predicted by the dark matter-nucleon effective theory. For current experiments associated with a null result, we find strong correlations between some pairs of coupling constants. For experiments that claim a signal (i.e., CoGeNT and DAMA), we find that pairs of coupling constants produce degenerate results.

  18. Neutrinos from Kaluza-Klein dark matter in the Sun

    E-Print Network [OSTI]

    Mattias Blennow; Henrik Melbeus; Tommy Ohlsson

    2010-01-26

    We investigate indirect neutrino signals from annihilations of Kaluza-Klein dark matter in the Sun. Especially, we examine a five- as well as a six-dimensional model, and allow for the possibility that boundary localized terms could affect the spectrum to give different lightest Kaluza-Klein particles, which could constitute the dark matter. The dark matter candidates that are interesting for the purpose of indirect detection of neutrinos are the first Kaluza-Klein mode of the U(1) gauge boson and the neutral component of the SU(2) gauge bosons. Using the DarkSUSY and WimpSim packages, we calculate muon fluxes at an Earth-based neutrino telescope, such as IceCube. For the five-dimensional model, the results that we obtained agree reasonably well with the results that have previously been presented in the literature, whereas for the six-dimensional model, we find that, at tree-level, the results are the same as for the five-dimensional model. Finally, if the first Kaluza-Klein mode of the U(1) gauge boson constitutes the dark matter, IceCube can constrain the parameter space. However, in the case that the neutral component of the SU(2) gauge bosons is the LKP, the signal is too weak to be observed.

  19. Dark Matter from Late Invisible Decays to/of Gravitinos

    E-Print Network [OSTI]

    Rouzbeh Allahverdi; Bhaskar Dutta; Farinaldo S. Queiroz; Louis E. Strigari; Mei-Yu Wang

    2014-12-27

    In this work, we sift a simple supersymmetric framework of late invisible decays to/of the gravitino. We investigate two cases where the gravitino is the lightest supersymmetric particle or the next-to-lightest supersymmetric particle. The next-to-lightest supersymmetric particle decays into two dark matter candidates and has a long lifetime due to gravitationally suppressed interactions. However, because of the absence of any hadronic or electromagnetic products, it satisfies the tight bounds set by big bang nucleosynthesis and cosmic microwaved background. One or both of the dark matter candidates produced in invisible decays can contribute to the amount of dark radiation and suppress perturbations at scales that are being probed by the galaxy power spectrum and the Lyman-alpha forest data. We show that these constraints are satisfied in large regions of the parameter space and, as a result, the late invisible decays to/of the gravitino can be responsible for the entire dark matter relic abundance.

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Visible and dark matter from a first-order phase transition in a baryon-symmetric universe

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

    Petraki, Kalliopi; Trodden, Mark; Volkas, Raymond R.

    2012-02-28

    The similar cosmological abundances observed for visible and dark matter suggest a common origin for both. By viewing the dark matter density as a dark-sector asymmetry, mirroring the situation in the visible sector, we show that the visible and dark matter asymmetries may have arisen simultaneously through a first-order phase transition in the early universe. The additional scalar particles in the theory can mix with the standard Higgs boson and provide other striking signatures.

  7. 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}?

  8. GeV-scale dark matter: Production at the Main Injector

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

    Dobrescu, Bogdan A.; Frugiuele, Claudia

    2015-02-03

    Assuming that dark matter particles interact with quarks via a GeV-scale mediator, we study dark matter production in fixed target collisions. The ensuing signal in a neutrino near detector consists of neutral-current events with an energy distribution peaked at higher values than the neutrino background. We find that for a Z' boson of mass around a few GeV that decays to dark matter particles, the dark matter beam produced by the Main Injector at Fermilab allows the exploration of a range of values for the gauge coupling that currently satisfy all experimental constraints. The NO?A near detector is well positionedmore »for probing the presence of a dark matter beam, and future LBNF near detectors would provide more sensitive probes.« less

  9. GeV-scale dark matter: Production at the Main Injector

    SciTech Connect (OSTI)

    Dobrescu, Bogdan A.; Frugiuele, Claudia

    2015-02-03

    Assuming that dark matter particles interact with quarks via a GeV-scale mediator, we study dark matter production in fixed target collisions. The ensuing signal in a neutrino near detector consists of neutral-current events with an energy distribution peaked at higher values than the neutrino background. We find that for a Z' boson of mass around a few GeV that decays to dark matter particles, the dark matter beam produced by the Main Injector at Fermilab allows the exploration of a range of values for the gauge coupling that currently satisfy all experimental constraints. The NO?A near detector is well positioned for probing the presence of a dark matter beam, and future LBNF near detectors would provide more sensitive probes.

  10. Hypothetical Dark Matter/Axion rockets: What can be said about Dark Matter in terms of space physics propulsion

    SciTech Connect (OSTI)

    Beckwith, Andrew [APS/Fermi contractor Aurora, Illinois 60502 630-840-2201 (United States)

    2009-03-16

    This paper discusses dark matter (DM) particle candidates from non-supersymmetry (SUSY) processes and explores how a DM candidate particle in the 100-400 GeV range could be created. Thrust from DM particles is also proposed for Photon rocket and Axion rockets. It would use a magnetic field to convert DM particles to near photonlike particles in a chamber to create thrust from the discharge of the near-photon-like particles. The presence of DM particles would suggest that thrust from the emerging near-photon-like particle would be greater than with conventional photon rockets. This amplifies and improves on an 'axion rocket ramjet' for interstellar travel. It is assumed that the same methodology used in an axion ramjet could be used with DM, with perhaps greater thrust/power conversion efficiencies.

  11. 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.

  12. DarkSUSY - A numerical package for dark matter calculations in the MSSM

    E-Print Network [OSTI]

    Paolo Gondolo; Joakim Edsjo; Lars Bergstrom; Piero Ullio; Edward A. Baltz

    2000-12-11

    The question of the nature of the dark matter in the Universe remains one of the most outstanding unsolved problems in basic science. One of the best motivated particle physics candidates is the lightest supersymmetric particle, assumed to be the lightest neutralino. We here describe DarkSUSY, an advanced numerical FORTRAN package for supersymmetric dark matter calculations which we release for public use. With the help of this package, the masses and compositions of various supersymmetric particles can be computed, for given input parameters of the minimal supersymmetric extension of the Standard Model (MSSM). For the lightest neutralino, the relic density is computed, using accurate methods which include the effects of resonances, pair production thresholds and coannihilations. Accelerator bounds are checked to identify viable dark matter candidates. Finally, detection rates are computed for a variety of detection methods, such as direct detection and indirect detection through antiprotons, gamma-rays and positrons from the Galactic halo or neutrinos from the center of the Earth or the Sun.

  13. Sterile Neutrinos and Light Dark Matter Save Each Other

    E-Print Network [OSTI]

    Chiu Man Ho; Robert J. Scherrer

    2013-03-13

    Short baseline neutrino experiments such as LSND and MiniBooNE seem to suggest the existence of light sterile neutrinos. Meanwhile, current cosmic microwave background (CMB) and big bang nucleosynthesis (BBN) measurements place an upper bound on the effective number of light neutrinos, $N_{eff}$ and the PLANCK satellite will measure $N_{eff}$ to a much higher accuracy and further constrain the number of sterile neutrinos allowed. We demonstrate that if an MeV dark matter particle couples more strongly to electrons and/or photons than to neutrinos, then p-wave annihilation after neutrino decoupling can reduce the value of $N_{eff}$ inferred from BBN and PLANCK. This mechanism can accommodate two eV sterile neutrinos even if PLANCK observes $N_{eff}$ as low as the standard model theoretical value of 3.046, and a large neutrino asymmetry is not needed to obtain the correct primordial element abundances. The dark matter annihilation also weakens the cosmological upper bounds on the neutrino masses, and we derive a relationship between the change in these bounds and the corresponding change in $N_{eff}$. Dark matter with an electric dipole moment or anapole moment is a natural candidate that exhibits the desired properties for this mechanism. Coincidentally, a dark matter particle with these properties and lighter than 3 MeV is precisely one that can explain the 511 keV gamma-ray line observed by INTEGRAL. We show that the addition of two eV sterile neutrinos allows this kind of dark matter to be lighter than 3 MeV, which is otherwise ruled out by the CMB bound on $N_{eff}$ if only active neutrinos are considered.

  14. 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.

  15. Identifying Dark Matter Burners in the Galactic center

    E-Print Network [OSTI]

    Moskalenko, Igor V

    2007-01-01

    If the supermassive black hole (SMBH) at the center of our Galaxy grew adiabatically, then a dense "spike" of dark matter is expected to have formed around it. Assuming that dark matter is composed primarily of weakly interacting massive particles (WIMPs), a star orbiting close enough to the SMBH can capture 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, i.e. "WIMP burners", in the vicinity of an adiabatically grown SMBH. We find that the most efficient WIMP burners are stars with degenerate electron cores, e.g. white dwarfs (WD) or degenerate cores with envelopes. If found, such stars would provide evidence for the existence of particle dark matter and could possibly be used to establish its density profile. In our previous paper we computed the luminosity from WIMP burning for a range of dark ma...

  16. 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 ...

  17. 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 ...

  18. Analysis of vacuum and argon gas fill data from the MiniCLEAN dark matter experiment

    E-Print Network [OSTI]

    Jaditz, Stephen H

    2015-01-01

    The existence of particle dark matter provides a consistent framework for understanding many astronomical observations. The rotation curves of galaxies and galaxyclusters, for example, indicate the majority of mass in these ...

  19. Connection between a possible fifth force and the direct detection of Dark Matter

    E-Print Network [OSTI]

    Jo Bovy; Glennys R. Farrar

    2008-08-12

    If there is a fifth force in the dark sector and dark sector particles interact non-gravitationally with ordinary matter, quantum corrections generically lead to a fifth force in the visible sector. We show how the strong experimental limits on fifth forces in the visible sector constrain the direct detection cross section, and the strength of the fifth force in the dark sector. If the latter is comparable to gravity, the spin-independent direct detection cross section must typically be <~ 10^{-55} cm^2. The anomalous acceleration of ordinary matter falling towards dark matter is also constrained: \\eta_{OM-DM} <~ 10^{-8}.

  20. 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.

  1. 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 ...

  2. The Isotropic Radio Background and Annihilating Dark Matter

    SciTech Connect (OSTI)

    Hooper, Dan; Belikov, Alexander V.; Jeltema, Tesla E.; Linden, Tim; Profumo, Stefano; Slatyer, Tracy R.

    2012-11-01

    Observations by ARCADE-2 and other telescopes sensitive to low frequency radiation have revealed the presence of an isotropic radio background with a hard spectral index. The intensity of this observed background is found to exceed the flux predicted from astrophysical sources by a factor of approximately 5-6. In this article, we consider the possibility that annihilating dark matter particles provide the primary contribution to the observed isotropic radio background through the emission of synchrotron radiation from electron and positron annihilation products. For reasonable estimates of the magnetic fields present in clusters and galaxies, we find that dark matter could potentially account for the observed radio excess, but only if it annihilates mostly to electrons and/or muons, and only if it possesses a mass in the range of approximately 5-50 GeV. For such models, the annihilation cross section required to normalize the synchrotron signal to the observed excess is sigma v ~ (0.4-30) x 10^-26 cm^3/s, similar to the value predicted for a simple thermal relic (sigma v ~ 3 x 10^-26 cm^3/s). We find that in any scenario in which dark matter annihilations are responsible for the observed excess radio emission, a significant fraction of the isotropic gamma ray background observed by Fermi must result from dark matter as well.

  3. Neutralino Gamma-ray Signals from Accreting Halo Dark Matter

    E-Print Network [OSTI]

    Lars Bergstrom; Joakim Edsjo; Christofer Gunnarsson

    2000-12-15

    There is mounting evidence that a self-consistent model for particle cold dark matter has to take into consideration spatial inhomogeneities on sub-galactic scales seen, for instance, in high-resolution N-body simulations of structure formation. Also in more idealized, analytic models, there appear density enhancements in certain regions of the halo. We use the results from a recent N-body simulation of the Milky Way halo and investigate the gamma-ray flux which would be produced when a specific dark matter candidate, the neutralino, annihilates in regions of enhanced density. The clumpiness found on all scales in the simulation results in very strong gamma-ray signals which seem to already rule out some regions of the supersymmetric parameter space, and would be further probed by upcoming experiments, such as the GLAST gamma-ray satellite. As an orthogonal model of structure formation, we also consider Sikivie's simple infall model of dark matter which predicts that there should exist continuous regions of enhanced density, caustic rings, in the dark matter halo of the Milky Way. We find, however, that the gamma-ray signal from caustic rings is generally too small to be detectable.

  4. Dark Matter Constraints from a Cosmic Index of Refraction

    SciTech Connect (OSTI)

    Gardner, Susan; Latimer, David C.

    2009-04-01

    The dark-matter candidates of particle physics invariably possess electromagnetic interactions, if only via quantum fluctuations. Taken en masse, dark matter can thus engender an index of refraction which deviates from its vacuum value. Its presence is signaled through frequency-dependent effects: the real part yields dispersive effects in propagation, and the imaginary part yields such in attenuation. We discuss theoretical constraints on the expansion of the index of refraction with frequency, the physical interpretation of the terms, and the particular observations needed to isolate its coefficients. This, with the advent of new opportunities to view gamma-ray bursts at cosmological distance scales, gives us a new probe of dark matter. As a first application we use the time delay determined from radio afterglow observations of gamma-ray bursts to limit the charge-to-mass ratio of dark matter to |{var_epsilon}|/M < 1.8 x 10{sup -5} eV{sup -1} at 95% CL.

  5. 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...

  6. 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 ...

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. Cold Dark Matter, Radiative Neutrino Mass, mu to e gamma, and Neutrinoless Double Beta Decay

    E-Print Network [OSTI]

    Jisuke Kubo; Ernest Ma; Daijiro Suematsu

    2006-08-24

    Two of the most important and pressing questions in cosmology and particle physics are: (1) What is the nature of cold dark matter? and (2) Will near-future experiments on neutrinoless double beta decay be able to ascertain that the neutrino is a Majorana particle, i.e. its own antiparticle? We show that these two seemingly unrelated issues are intimately connected if neutrinos acquire mass only because of their interactions with dark matter.

  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. 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.

  17. 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.

  18. Fermionic dark matter with pseudo-scalar Yukawa interaction

    SciTech Connect (OSTI)

    Ghorbani, Karim

    2015-01-01

    We consider a renormalizable extension of the standard model whose fermionic dark matter (DM) candidate interacts with a real singlet pseudo-scalar via a pseudo-scalar Yukawa term while we assume that the full Lagrangian is CP-conserved in the classical level. When the pseudo-scalar boson develops a non-zero vacuum expectation value, spontaneous CP-violation occurs and this provides a CP-violated interaction of the dark sector with the SM particles through mixing between the Higgs-like boson and the SM-like Higgs boson. This scenario suggests a minimal number of free parameters. Focusing mainly on the indirect detection observables, we calculate the dark matter annihilation cross section and then compute the DM relic density in the range up to m{sub DM} = 300 GeV.We then find viable regions in the parameter space constrained by the observed DM relic abundance as well as invisible Higgs decay width in the light of 125 GeV Higgs discovery at the LHC. We find that within the constrained region of the parameter space, there exists a model with dark matter mass m{sub DM} ? 38 GeV annihilating predominantly into b quarks, which can explain the Fermi-LAT galactic gamma-ray excess.

  19. On the minimum dark matter mass testable by neutrinos from the Sun

    SciTech Connect (OSTI)

    Busoni, Giorgio; Simone, Andrea De; Huang, Wei-Chih E-mail: andrea.desimone@sissa.it

    2013-07-01

    We discuss a limitation on extracting bounds on the scattering cross section of dark matter with nucleons, using neutrinos from the Sun. If the dark matter particle is sufficiently light (less than about 4 GeV), the effect of evaporation is not negligible and the capture process goes in equilibrium with the evaporation. In this regime, the flux of solar neutrinos of dark matter origin becomes independent of the scattering cross section and therefore no constraint can be placed on it. We find the minimum values of dark matter masses for which the scattering cross section on nucleons can be probed using neutrinos from the Sun. We also provide simple and accurate fitting functions for all the relevant processes of GeV-scale dark matter in the Sun.

  20. 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.

  1. Hints on the nature of dark matter from the properties of Milky Way satellites

    SciTech Connect (OSTI)

    Anderhalden, Donnino; Diemand, Juerg [Institute for Theoretical Physics, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland); Schneider, Aurel [Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH (United Kingdom); Macciò, Andrea V. [Max-Planck-Institute for Astronomy, Königstuhl 17, 69117 Heidelberg (Germany); Bertone, Gianfranco, E-mail: donninoa@physik.uzh.ch, E-mail: aurel.schneider@sussex.ac.uk, E-mail: maccio@mpia.de, E-mail: diemand@physik.uzh.ch, E-mail: gf.bertone@gmail.com [GRAPPA Institute, University of Amsterdam, Science Park 904, 1090 GL Amsterdam (Netherlands)

    2013-03-01

    The nature of dark matter is still unknown and one of the most fundamental scientific mysteries. Although successfully describing large scales, the standard cold dark matter model (CDM) exhibits possible shortcomings on galactic and sub-galactic scales. It is exactly at these highly non-linear scales where strong astrophysical constraints can be set on the nature of the dark matter particle. While observations of the Lyman-? forest probe the matter power spectrum in the mildly non-linear regime, satellite galaxies of the Milky Way provide an excellent laboratory as a test of the underlying cosmology on much smaller scales. Here we present results from a set of high resolution simulations of a Milky Way sized dark matter halo in eight distinct cosmologies: CDM, warm dark matter (WDM) with a particle mass of 2 keV and six different cold plus warm dark matter (C+WDM) models, varying the fraction, f{sub wdm}, and the mass, m{sub wdm}, of the warm component. We used three different observational tests based on Milky Way satellite observations: the total satellite abundance, their radial distribution and their mass profile. We show that the requirement of simultaneously satisfying all three constraints sets very strong limits on the nature of dark matter. This shows the power of a multi-dimensional small scale approach in ruling out models which would be still allowed by large scale observations.

  2. 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...

  3. 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.

  4. 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.

  5. 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 ...

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Dark matter relic density in Gauss-Bonnet 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 [College of Science, Technology and Engineering, James Cook University, 1 James Cook Dr., Townsville 4811 (Australia)

    2014-12-01

    The relic density of symmetric and asymmetric dark matter in a Gauss-Bonnet (GB) modified Randall-Sundrum (RS) type II braneworld cosmology is investigated. The existing study of symmetric dark matter in a GB braneworld (Okada and Okada, 2009) found that the expansion rate was reduced compared to that in standard General Relativity (GR), thereby delaying particle freeze-out and resulting in relic abundances which are suppressed by up to O(10{sup ?2}). This is in direct contrast to the behaviour observed in RS braneworlds where the expansion rate is enhanced and the final relic abundance boosted. However, this finding that relic abundances are suppressed in a GB braneworld is based upon a highly contrived situation in which the GB era evolves directly into a standard GR era, rather than passing through a RS era as is the general situation. This collapse of the RS era requires equating the mass scale m{sub ?} of the GB modification and the mass scale m{sub ?} of the brane tension. However, if the GB contribution is to be considered as the lowest order correction from string theory to the RS action, we would expect m{sub ?} > m{sub ?}. We investigate the effect upon the relic abundance of choosing more realistic values for the ratio R{sub m} ? m{sub ?}/m{sub ?} and find that the relic abundance can be either enhanced or suppressed by more than two orders of magnitude. However, suppression only occurs for a small range of parameter choices and, overwhelmingly, the predominant situation is that of enhancement as we recover the usual Randall-Sundrum type behaviour in the limit R{sub m} >> 1. We use the latest observational bound ?{sub DM}h{sup 2} = 0.1187 ± 0.0017 to constrain the various model parameters and briefly discuss the implications for direct/indirect dark matter detection experiments as well as dark matter particle models.

  11. 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...

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. Phenomenology of Dark Matter via a Bimetric Extension of General Relativity

    E-Print Network [OSTI]

    Laura Bernard; Luc Blanchet

    2015-05-20

    We propose a relativistic model of dark matter reproducing at once the concordance cosmological model $\\Lambda$-Cold-Dark-Matter ($\\Lambda$-CDM) at cosmological scales, and the phenomenology of the modified Newtonian dynamics (MOND) at galactic scales. To achieve this we postulate a non-standard form of dark matter, consisting of two different species of particles coupled to gravity via a bimetric extension of general relativity, and linked together through an internal vector field (a "graviphoton") generated by the mass of these particles. We prove that this dark matter behaves like ordinary cold dark matter at the level of first order cosmological perturbation, while a pure cosmological constant plays the role of dark energy. The MOND equation emerges in the non-relativistic limit through a mechanism of gravitational polarization of the dark matter medium in the gravitational field of ordinary matter. Finally we show that the model is viable in the solar system as it predicts the same parametrized post-Newtonian parameters as general relativity.

  17. 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.

  18. Cogeneration of Dark Matter and Baryons by Non-Standard-Model Sphalerons

    E-Print Network [OSTI]

    Barr, S M

    2013-01-01

    Sphalerons of a new gauge interaction can convert a primordial asymmetry in B or L into a dark matter asymmetry. From the equilibrium conditions for the sphalerons of both the electroweak and the new interactions, one can compute the ratios of B, L, and X, where X is the dark matter number, thus determining the mass of the dark matter particle fairly precisely. Such a scenario can arise naturally in the context of unification with larger groups. An illustrative model embeddable in $SU(6) \\times SU(2) \\subset E_6$ is described.

  19. Cogeneration of Dark Matter and Baryons by Non-Standard-Model Sphalerons in Unified Models

    E-Print Network [OSTI]

    S. M. Barr; Heng-Yu Chen

    2013-09-17

    Sphalerons of a new gauge interaction can convert a primordial asymmetry in B or L into a dark matter asymmetry. From the equilibrium conditions for the sphalerons of both the electroweak and the new interactions, one can compute the ratios of B, L, and X, where X is the dark matter number, thus determining the mass of the dark matter particle fairly precisely. Such a scenario can arise naturally in the context of unification with larger groups. An illustrative model embeddable in $SU(6) \\times SU(2) \\subset E_6$ is described as well as an equally simple model based on SU(7).

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Cold dark matter cosmology conflicts with fluid mechanics and observations

    E-Print Network [OSTI]

    Carl H. Gibson

    2006-10-23

    Cold dark matter hierarchical clustering (CDMHC) cosmology based on the Jeans 1902 criterion for gravitational instability gives predictions about the early universe contrary to fluid mechanics and observations. Jeans neglected viscosity, diffusivity, and turbulence: factors that determine gravitational structure formation and contradict small structures (CDM halos) forming from non-baryonic dark matter particle candidates. From hydro-gravitational-dynamics (HGD) cosmology, viscous-gravitational fragmentation produced supercluster (10^46 kg), cluster, and galaxy-mass (10^42 kg) clouds in the primordial plasma with the large fossil density turbulence (rho_o ~ 3x10-17 kg m-3) of the first fragmentation at 10^12 s, and a protogalaxy linear and spiral clump morphology reflecting maximum stretching near vortex lines of the plasma turbulence at the 10^13 s plasma-gas transition. Gas protogalaxies fragmented into proto-globular-star-cluster mass (10^36 kg) clumps of protoplanet gas clouds that are now frozen as earth-mass (10^24-^25 kg) Jovian planets of the baryonic dark matter, about 30,000,000 rogue planets per star. Observations contradict the CDMHCC prediction of large explosive Population III first stars at 10^16 s, but support the immediate gentle formation of small Population II first stars at 10^13 s in globular-star-clusters from HGD.

  5. 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.

  6. Generalised form factor dark matter in the Sun

    E-Print Network [OSTI]

    Aaron C. Vincent; Aldo Serenelli; Pat Scott

    2015-04-16

    We study the effects of energy transport in the Sun by asymmetric dark matter with momentum and velocity-dependent interactions, with an eye to solving the decade-old Solar Abundance Problem. We study effective theories where the dark matter-nucleon scattering cross-section goes as $v_{\\rm rel}^{2n}$ and $q^{2n}$ with $n = -1, 0, 1 $ or $2$, where $v_{\\rm rel}$ is the dark matter-nucleon relative velocity and $q$ is the momentum exchanged in the collision. Such cross-sections can arise generically as leading terms from the most basic nonstandard DM-quark operators. We employ a high-precision solar simulation code to study the impact on solar neutrino rates, the sound speed profile, convective zone depth, surface helium abundance and small frequency separations. We find that the majority of models that improve agreement with the observed sound speed profile and depth of the convection zone also reduce neutrino fluxes beyond the level that can be reasonably accommodated by measurement and theory errors. However, a few specific points in parameter space yield a significant overall improvement. A 3-5 GeV DM particle with $\\sigma_{SI} \\propto q^2$ is particularly appealing, yielding more than a $6\\sigma$ improvement with respect to standard solar models, while being allowed by direct detection and collider limits. We provide full analytical capture expressions for $q$- and $v_{\\rm rel}$-dependent scattering, as well as complete likelihood tables for all models.

  7. 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.

  8. 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.

  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. 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...

  12. 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.

  13. Probing interactions within the dark matter sector via extra radiation contributions

    E-Print Network [OSTI]

    Urbano Franca; Roberto A. Lineros; Joaquim Palacio; Sergio Pastor

    2013-05-15

    The nature of dark matter is one of the most thrilling riddles for both cosmology and particle physics nowadays. While in the typical models the dark sector is composed only by weakly interacting massive particles, an arguably more natural scenario would include a whole set of gauge interactions which are invisible for the standard model but that are in contact with the dark matter. We present a method to constrain the number of massless gauge bosons and other relativistic particles that might be present in the dark sector using current and future cosmic microwave background data, and provide upper bounds on the size of the dark sector. We use the fact that the dark matter abundance depends on the strength of the interactions with both sectors, which allows one to relate the freeze-out temperature of the dark matter with the temperature of {this cosmic background of dark gauge bosons}. This relation can then be used to calculate how sizable is the impact of the relativistic dark sector in the number of degrees of freedom of the early Universe, providing an interesting and testable connection between cosmological data and direct/indirect detection experiments. The recent Planck data, in combination with other cosmic microwave background experiments and baryonic acoustic oscillations data, constrains the number of relativistic dark gauge bosons, when the freeze-out temperature of the dark matter is larger than the top mass, to be N \\lesssim 14 for the simplest scenarios, while those limits are slightly relaxed for the combination with the Hubble constant measurements to N \\lesssim 20. Future releases of Planck data are expected to reduce the uncertainty by approximately a factor 3, what will reduce significantly the parameter space of allowed models.

  14. 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.

  15. 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.

  16. Dark Matter and the Baryon Asymmetry of the Universe

    E-Print Network [OSTI]

    Glennys R. Farrar; Gabrijela Zaharijas

    2004-07-06

    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 $\\gsi 10%$, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$.

  17. Gamma-Ray Bursts and Dark Matter - a joint origin?

    E-Print Network [OSTI]

    Daniel Enstrom

    1998-10-14

    A scenario is presented where large quark-gluon plasma (QGP) objects escaping the quark-hadron transition in the early Universe account for the baryonic dark matter as well as act as the sources for gamma-ray bursts. Two basic assumptions are made. Firstly, we assume that a QGP consisting of u,d and s quarks is the absolute ground state of QCD and secondly, that the quark-hadron transition in the early Universe was of first order. Both particle physics and astrophysics constraints are discussed, mainly from an observational point of view.

  18. 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.

  19. 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\

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Testing Higgs portal dark matter via $Z$ fusion at a linear collider

    E-Print Network [OSTI]

    Shinya Kanemura; Shigeki Matsumoto; Takehiro Nabeshima; Hiroyuki Taniguchi

    2011-02-25

    We investigate the possibility of detecting dark matter at TeV scale linear colliders in the scenario where the dark matter is a massive particle weakly interacting only with the Higgs boson $h$ in the low energy effective theory (the Higgs portal dark matter scenario). The dark matter in this scenario would be difficult to be tested at the CERN Large Hadron Collider when the decay of the Higgs boson into a dark matter pair is not kinematically allowed. We study whether even in such a case the dark matter $D$ can be explored or not via the $Z$ boson fusion process at the International Linear Collider and also at a multi TeV lepton collider. It is found that for the collision energy $\\sqrt{S}>1$ TeV with the integrated luminosity 1 ab$^{-1}$, the signal ($e^{\\pm}e^-\\to e^{\\pm}e^-h^\\ast \\to e^{\\pm}e^-DD$) can be seen after appropriate kinematic cuts. In particular, when the dark matter is a fermion or a vector, which is supposed to be singlet under the standard gauge symmetry, the signal with the mass up to 100 GeV can be tested for the Higgs boson mass to be 120 GeV.

  6. 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.

  7. 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.

  8. Constraining Effective Self Interactions of Fermionic Dark Matter

    E-Print Network [OSTI]

    Modak, Kamakshya Prasad

    2015-01-01

    The idea of Dark Matter (DM) with self interaction was invoked to resolve a number of discrepancies between the simulation based predictions by collisionless cold DM and the astrophysical observations on galactic and subgalactic scales. Evidences for self interaction would have striking implications for particle nature of DM. In order to reconcile such astrophysical observations for self interaction with particle properties for DM, we consider the general scenario of self interacting Dirac fermionic DM, $\\chi$. Also since the exact particle physics model for DM is yet to be probed, we simply adopt the effective model independent framework for DM self interaction which occurs via the most general effective 4-fermion operators invariant under both Lorentz and CPT transformations. From the thorough investigation of the interrelations among the parameters in this framework, namely, the effective DM self couplings ($G_{i}$), DM mass ($m_{\\chi}$) and relative velocity ($v_{\\rm rel}$), it can be inferred that $G_{i}...

  9. The positron excess as a smoking gun for dynamical dark matter?

    SciTech Connect (OSTI)

    Dienes, Keith R.; Kumar, Jason; Thomas, Brooks

    2014-06-24

    One of the most puzzling aspects of recent data from the AMS-02 experiment is an apparent rise in the cosmic-ray positron fraction as a function of energy. This feature is observed out to energies of approximately 350 GeV. One explanation of these results interprets the extra positrons as arising from the decays of dark-matter particles. This in turn typically requires that such particles have rather heavy TeV-scale masses and not undergo simple two-body decays to leptons. In this talk, by contrast, we show that Dynamical Dark Matter (DDM) can not only match existing AMS-02 data on the positron excess, but also accomplish this feat with significantly lighter dark-matter constituents undergoing simple two-body decays to leptons. We also demonstrate that the Dynamical Dark Matter framework makes a fairly robust prediction that the positron fraction should level off and then remain roughly constant out to approximately 1 TeV, without experiencing any sharp downturns. Thus, if we interpret the positron excess in terms of decaying dark matter, the existence of a plateau in the positron fraction at energies less than 1 TeV may be taken as a “smoking gun” of Dynamical Dark Matter.

  10. 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.

  11. 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...

  12. 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.

  13. Connection between a Possible Fifth Force and the Direct Detection of Dark Matter

    SciTech Connect (OSTI)

    Bovy, Jo; Farrar, Glennys R. [Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, New York 10003 (United States)

    2009-03-13

    If there were a fifth force in the dark sector and dark matter (DM) particles interacted nongravitationally with ordinary matter, quantum corrections generically would lead to a fifth force in the visible sector. We show how the strong experimental limits on fifth forces in the visible sector produce bounds on the cross section for DM detection and the strength of the fifth force in the dark sector. For a fifth force comparable in strength to gravity, the spin-independent direct detection cross section must typically be < or approx. 10{sup -55} cm{sup 2}. The anomalous acceleration of ordinary matter falling towards dark matter would also be constrained: {eta}{sub OM-DM} or approx. 10{sup -8}.

  14. 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...

  15. Flavored Dark Matter and the Galactic Center Gamma-Ray Excess

    SciTech Connect (OSTI)

    Agrawal, Prateek; Batell, Brian; Hooper, Dan; Lin, Tongyan

    2014-09-01

    Thermal relic dark matter particles with a mass of 31-40 GeV and that dominantly annihilate to bottom quarks have been shown to provide an excellent description of the excess gamma rays observed from the center of the Milky Way. Flavored dark matter provides a well-motivated framework in which the dark matter can dominantly couple to bottom quarks in a flavor-safe manner. We propose a phenomenologically viable model of bottom flavored dark matter that can account for the spectral shape and normalization of the gamma-ray excess while naturally suppressing the elastic scattering cross sections probed by direct detection experiments. This model will be definitively tested with increased exposure at LUX and with data from the upcoming high-energy run of the Large Hadron Collider (LHC).

  16. Dark Matter and Synchrotron Emission from Galactic Center Radio Filaments

    SciTech Connect (OSTI)

    Linden, Tim; Hooper, Dan; Yusef-Zadeh, Farhad

    2011-11-10

    The inner degrees of the Galactic center contain a large population of filamentary structures observed at radio frequencies. These so-called non-thermal radio filaments (NRFs) trace magnetic field lines and have attracted significant interest due to their hard (S_v ~ -0.1 +/- 0.4) synchrotron emission spectra. The origin of these filaments remains poorly understood. We show that the electrons and positrons created through the annihilations of a relatively light (~5-10 GeV) dark matter particle with the cross section predicted for a simple thermal relic can provide a compelling match to the intensity, spectral shape, and flux variation of the NRFs. Furthermore, the characteristics of the dark matter particle necessary to explain the synchrotron emission from the NRFs is consistent with those required to explain the excess gamma-ray emission observed from the Galactic center by the Fermi-LAT, as well as the direct detection signals observed by CoGeNT and DAMA/LIBRA.

  17. Dark matter transport properties and rapidly rotating neutron stars

    E-Print Network [OSTI]

    C. J. Horowitz

    2012-05-16

    Neutron stars are attractive places to look for dark matter because their high densities allow repeated interactions. Weakly interacting massive particles (WIMPs) may scatter efficiently in the core or in the crust of a neutron star. In this paper we focus on WIMP contributions to transport properties, such as shear viscosity or thermal conductivity, because these can be greatly enhanced by long mean free paths. We speculate that WIMPs increase the shear viscosity of neutron star matter and help stabilize r-mode oscillations. These are collective oscillations where the restoring force is the Coriolis force. At present r-modes are thought to be unstable in many observed rapidly rotating stars. If WIMPs stabilize the r-modes, this would allow neutron stars to spin rapidly. This likely requires WIMP-nucleon cross sections near present experimental limits and an appropriate density of WIMPs in neutron stars.

  18. Freeze-In Dark Matter with Displaced Signatures at Colliders

    E-Print Network [OSTI]

    Co, Raymond T; Hall, Lawrence J; Pappadopulo, Duccio

    2015-01-01

    Dark matter, $X$, may be generated by new physics at the TeV scale during an early matter-dominated (MD) era that ends at temperature $T_R \\ll {\\rm TeV}$. Compared to the conventional radiation-dominated (RD) results, yields from both Freeze-Out and Freeze-In processes are greatly suppressed by dilution from entropy production, making Freeze-Out less plausible while allowing successful Freeze-In with a much larger coupling strength. Freeze-In is typically dominated by the decay of a particle $B$ of the thermal bath, $B \\rightarrow X$. For a large fraction of the relevant cosmological parameter space, the decay rate required to produce the observed dark matter abundance leads to displaced signals at LHC and future colliders, for any $m_X$ in the range ${\\rm keV} < m_X < m_B$ and for values of $m_B$ accessible to these colliders. This result applies whether the early MD era arises after conventional inflation, when $T_R$ is the usual reheat temperature, or is a generic MD era with an alternative origin. I...

  19. IDMS: Inert Dark Matter Model with a complex singlet

    E-Print Network [OSTI]

    Cesar Bonilla; Dorota Sokolowska; Neda Darvishi; J. Lorenzo Diaz-Cruz; Maria Krawczyk

    2015-04-13

    Within the Inert Doublet Model (IDM) there is a viable dark matter candidate. This simple model can provide a strong enough first order phase transition, which is required in order to account for the matter-antimatter asymmetry in the Universe (BAU). However, another necessary ingredient is missing, as there is no additional source of CP violation in the IDM, besides the standard CKM phase from the Standard Model. Additional CP violating phase can appear if a complex singlet of $SU(3)_C \\times SU(2)_W \\times U(1)_Y$ with a non-zero vacuum expectation value is added to the scalar sector of the IDM. We construct the scalar potential of the inert doublet plus singlet model (IDMS), assuming an exact $Z_2$ symmetry, with singlet being $Z_2$-even. To simplify the model we use a softly broken $U(1)$ symmetry, which allows a reduction of the number of free parameters in the potential. We study the masses and interactions of scalar particles for a few benchmark scenarios. Constraints from collider physics, in particular from the Higgs signal observed at LHC with $M_h\\approx 125$ GeV are discussed, as well as constraints from the dark matter experiments.

  20. 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

  1. Baryon Asymmetry and Dark Matter Through the Vector-Like Portal

    E-Print Network [OSTI]

    Pavel Fileviez Perez; Mark B. Wise

    2013-05-14

    A possible connection between the cosmological baryon asymmetry, dark matter and vector-like fermions is investigated. In this scenario an asymmetry generated through baryogenesis or leptogenesis (in the vector-like matter sector) connects the baryon asymmetry to the dark matter density. We present explicit renormalizable models where this connection occurs. These models have asymmetric dark matter and a significant invisible Higgs decay width to dark matter particles is possible. We refer to this type of scenario as the vector-like portal. In some asymmetric dark matter models there are potential naturalness issues for the low energy effective theory. We address that issue in the models we consider by starting with a Lagrangian that is the most general renormalizable one consistent with the gauge (and discrete) symmetries and showing the low energy effective theory automatically has the required form as a consequence of the symmetries of the full theory. We show that the mass of the dark matter candidate is predicted in these scenarios.

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

    E-Print Network [OSTI]

    Homer G. Ellis

    2015-03-15

    In creating his gravitational field equations Einstein assumed without justification that inertial mass, even in its equivalent form as energy, is a source of gravity. Giving up that assumption allows modifying the field equations to a form in which a positive cosmological constant is seen to (mis)represent a uniform negative net mass density of gravitationally attractive and gravitationally repulsive matter. Field equations with both positive and negative active gravitational mass densities of both primordial and continuously created matter incorporated, along with two scalar fields to 'relax the constraints' on the space-time geometry, yield cosmological solutions that exhibit inflation, deceleration, coasting, acceleration, and a 'big bounce' instead of a 'big bang', and provide good fits to a Hubble diagram of type Ia supernovae data. The repulsive matter is identified as the back sides of the 'drainholes' introduced by the author in 1973 as solutions of those same field equations. Drainholes are topological tunnels in space which gravitationally attract on their front, entrance sides and repel more strongly on their back, exit sides. The front sides serve both as the gravitating cores of the visible, baryonic particles of primordial matter and as the continuously created, invisible particles of the 'dark matter' needed to hold together the large scale structures seen in the universe; the back sides serve as the misnamed 'dark energy' driving the current acceleration of the expansion of the universe. Formation of cosmic voids, walls, filaments, and nodes is attributed to expulsion of drainhole entrances from regions populated by drainhole exits, and accumulation of the entrances on boundaries separating those regions.

  3. 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.

  4. 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.

  5. Solar Gamma Rays Powered by Secluded Dark Matter

    E-Print Network [OSTI]

    Brian Batell; Maxim Pospelov; Adam Ritz; Yanwen Shang

    2009-10-08

    Secluded dark matter models, in which WIMPs annihilate first into metastable mediators, can present novel indirect detection signatures in the form of gamma rays and fluxes of charged particles arriving from directions correlated with the centers of large astrophysical bodies within the solar system, such as the Sun and larger planets. This naturally occurs if the mean free path of the mediator is in excess of the solar (or planetary) radius. We show that existing constraints from water Cerenkov detectors already provide a novel probe of the parameter space of these models, complementary to other sources, with significant scope for future improvement from high angular resolution gamma-ray telescopes such as Fermi-LAT. Fluxes of charged particles produced in mediator decays are also capable of contributing a significant solar system component to the spectrum of energetic electrons and positrons, a possibility which can be tested with the directional and timing information of PAMELA and Fermi.

  6. 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.

  7. Cosmological dark matter annihilations into gamma-rays - a closer look

    E-Print Network [OSTI]

    Piero Ullio; Lars Bergstrom; Joakim Edsjo; Cedric Lacey

    2002-07-04

    We investigate the prospects of detecting weakly interacting massive particle (WIMP) dark matter by measuring the contribution to the extragalactic gamma-ray radiation induced, in any dark matter halo and at all redshifts, by WIMP pair annihilations into high-energy photons. We perform a detailed analysis of the distinctive spectral features of this signal, recently proposed in a short letter by three of the authors, with emphasis on the signature due to monochromatic gamma-ray yields: the combined effect of cosmological redshift and absorption along the line of sight produces sharp bumps, peaked at the rest frame energy of the lines and asymmetrically smeared to lower energies. The level of the flux depends both on the particle physics scenario for WIMP dark matter and on the question of how dark matter clusters. Uncertainties introduced by the latter are thoroughly discussed implementing a realistic model inspired by results of the state-of-the-art N-body simulations and semi-analytic modeling in the cold dark matter structure formation theory. We also address the question of the potential gamma-ray background originating from blazars, presenting a novel calculation. Comparing the signal with the background, we find that there are viable configurations, in the combined parameter space defined by the particle physics setup and the structure formation scenario, for which the WIMP induced extragalactic gamma-ray signal will be detectable in the new generation of gamma-ray telescopes such as GLAST.

  8. 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.

  9. 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 ...

  10. 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.

  11. 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.

  12. Freeze-In Dark Matter with Displaced Signatures at Colliders

    E-Print Network [OSTI]

    Raymond T. Co; Francesco D'Eramo; Lawrence J. Hall; Duccio Pappadopulo

    2015-06-24

    Dark matter, $X$, may be generated by new physics at the TeV scale during an early matter-dominated (MD) era that ends at temperature $T_R \\ll {\\rm TeV}$. Compared to the conventional radiation-dominated (RD) results, yields from both Freeze-Out and Freeze-In processes are greatly suppressed by dilution from entropy production, making Freeze-Out less plausible while allowing successful Freeze-In with a much larger coupling strength. Freeze-In is typically dominated by the decay of a particle $B$ of the thermal bath, $B \\rightarrow X$. For a large fraction of the relevant cosmological parameter space, the decay rate required to produce the observed dark matter abundance leads to displaced signals at LHC and future colliders, for any $m_X$ in the range ${\\rm keV} < m_X < m_B$ and for values of $m_B$ accessible to these colliders. This result applies whether the early MD era arises after conventional inflation, when $T_R$ is the usual reheat temperature, or is a generic MD era with an alternative origin. In the former case, if $m_X$ is sufficiently large to be measured from kinematics, the reheat temperature $T_R$ can be extracted. Our result is independent of the particular particle physics implementation of $B \\rightarrow X$, and can occur via any operator of dimension less than 8 (4) for a post-inflation (general MD) cosmology. An interesting example is provided by DFS axion theories with TeV-scale supersymmetry and axino dark matter of mass GeV to TeV, which is typically overproduced in a conventional RD cosmology. If $B$ is the higgsino, $\\tilde h$, Higgs, W and Z particles appear at the displaced decays, $\\tilde h \\rightarrow h \\tilde a, Z \\tilde a$ and $\\tilde h^\\pm \\rightarrow W^\\pm \\tilde a$. The scale of axion physics, $f$, is predicted to be in the range $(3\\times10^8 - 10^{12})$ GeV and, over much of this range, can be extracted from the decay length.

  13. 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.

  14. (In)direct detection of boosted dark matter

    SciTech Connect (OSTI)

    Agashe, Kaustubh; Cui, Yanou; Necib, Lina; Thaler, Jesse E-mail: cuiyo@umd.edu E-mail: jthaler@mit.edu

    2014-10-01

    We initiate the study of novel thermal dark matter (DM) scenarios where present-day annihilation of DM in the galactic center produces boosted stable particles in the dark sector. These stable particles are typically a subdominant DM component, but because they are produced with a large Lorentz boost in this process, they can be detected in large volume terrestrial experiments via neutral-current-like interactions with electrons or nuclei. This novel DM signal thus combines the production mechanism associated with indirect detection experiments (i.e. galactic DM annihilation) with the detection mechanism associated with direct detection experiments (i.e. DM scattering off terrestrial targets). Such processes are generically present in multi-component DM scenarios or those with non-minimal DM stabilization symmetries. As a proof of concept, we present a model of two-component thermal relic DM, where the dominant heavy DM species has no tree-level interactions with the standard model and thus largely evades direct and indirect DM bounds. Instead, its thermal relic abundance is set by annihilation into a subdominant lighter DM species, and the latter can be detected in the boosted channel via the same annihilation process occurring today. Especially for dark sector masses in the 10 MeV–10 GeV range, the most promising signals are electron scattering events pointing toward the galactic center. These can be detected in experiments designed for neutrino physics or proton decay, in particular Super-K and its upgrade Hyper-K, as well as the PINGU/MICA extensions of IceCube. This boosted DM phenomenon highlights the distinctive signatures possible from non-minimal dark sectors.

  15. 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.

  16. 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.

  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. Light dark matter, naturalness, and the radiative origin of the electroweak scale

    SciTech Connect (OSTI)

    Altmannshofer, Wolfgang; Bardeen, William A.; Bauer, Martin; Carena, Marcela; Lykken, Joseph D.

    2015-01-01

    We study classically scale invariant models in which the Standard Model Higgs mass term is replaced in the Lagrangian by a Higgs portal coupling to a complex scalar field of a dark sector. We focus on models that are weakly coupled with the quartic scalar couplings nearly vanishing at the Planck scale. The dark sector contains fermions and scalars charged under dark SU(2) × U(1) gauge interactions. Radiative breaking of the dark gauge group triggers electroweak symmetry breaking through the Higgs portal coupling. Requiring both a Higgs boson mass of 125.5 GeV and stability of the Higgs potential up to the Planck scale implies that the radiative breaking of the dark gauge group occurs at the TeV scale. We present a particular model which features a long-range abelian dark force. The dominant dark matter component is neutral dark fermions, with the correct thermal relic abundance, and in reach of future direct detection experiments. The model also has lighter stable dark fermions charged under the dark force, with observable effects on galactic-scale structure. Collider signatures include a dark sector scalar boson with mass ? 250 GeV that decays through mixing with the Higgs boson, and can be detected at the LHC. The Higgs boson, as well as the new scalar, may have significant invisible decays into dark sector particles.

  19. Light dark matter, naturalness, and the radiative origin of the electroweak scale

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

    Altmannshofer, Wolfgang; Bardeen, William A.; Bauer, Martin; Carena, Marcela; Lykken, Joseph D.

    2015-01-01

    We study classically scale invariant models in which the Standard Model Higgs mass term is replaced in the Lagrangian by a Higgs portal coupling to a complex scalar field of a dark sector. We focus on models that are weakly coupled with the quartic scalar couplings nearly vanishing at the Planck scale. The dark sector contains fermions and scalars charged under dark SU(2) × U(1) gauge interactions. Radiative breaking of the dark gauge group triggers electroweak symmetry breaking through the Higgs portal coupling. Requiring both a Higgs boson mass of 125.5 GeV and stability of the Higgs potential up tomore »the Planck scale implies that the radiative breaking of the dark gauge group occurs at the TeV scale. We present a particular model which features a long-range abelian dark force. The dominant dark matter component is neutral dark fermions, with the correct thermal relic abundance, and in reach of future direct detection experiments. The model also has lighter stable dark fermions charged under the dark force, with observable effects on galactic-scale structure. Collider signatures include a dark sector scalar boson with mass ? 250 GeV that decays through mixing with the Higgs boson, and can be detected at the LHC. The Higgs boson, as well as the new scalar, may have significant invisible decays into dark sector particles.« less

  20. 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.

  1. 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.

  2. 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.

  3. Universal Two-body Physics in Dark Matter near an S-wave Resonance

    E-Print Network [OSTI]

    Eric Braaten; H. -W. Hammer

    2013-09-03

    The dark matter annihilation rate at small relative velocities can be amplified by a large boost factor using various mechanisms, including Sommerfeld enhancement, resonance enhancement, and Breit-Wigner enhancement. These mechanisms all involve a resonance near the threshold for a pair of dark matter particles. We point out that if the resonance is in the S-wave channel, the mechanisms are equivalent sufficiently near the resonance and they are constrained by universal two-body physics. The amplified annihilation rate requires a corresponding amplification of the elastic scattering cross section. If the resonance is a bound state below the threshold, it has an increased lifetime that is inversely proportional to the square root of the binding energy. Its spatial structure is that of two dark matter particles whose mean separation is also inversely proportional to the square root of the binding energy.

  4. Constraints on decaying dark matter from Fermi observations of nearby galaxies and clusters

    SciTech Connect (OSTI)

    Dugger, Leanna; Profumo, Stefano [Department of Astronomy and Department of Physics, University of California Berkeley, 601 Campbell Hall, Berkeley, CA (United States); Jeltema, Tesla E., E-mail: greentee01@gmail.com, E-mail: tesla@ucolick.org, E-mail: profumo@scipp.ucsc.edu [UCO/Lick Observatories, 1156 High St., Santa Cruz, CA 95064 (United States)

    2010-12-01

    We analyze the impact of Fermi gamma-ray observations (primarily non-detections) of selected nearby galaxies, including dwarf spheroidals, and of clusters of galaxies on decaying dark matter models. We show that the fact that galaxy clusters do not shine in gamma rays puts the most stringent limits available to-date on the lifetime of dark matter particles for a wide range of particle masses and decay final states. In particular, our results put strong constraints on the possibility of ascribing to decaying dark matter both the increasing positron fraction reported by PAMELA and the high-energy feature in the electron-positron spectrum measured by Fermi. Observations of nearby dwarf galaxies and of the Andromeda Galaxy (M31) do not provide as strong limits as those from galaxy clusters, while still improving on previous constraints in some cases.

  5. 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.

  6. 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

  7. Capture of Inelastic Dark Matter in the Sun

    E-Print Network [OSTI]

    Shmuel Nussinov; Lian-Tao Wang; Itay Yavin

    2009-09-02

    We consider the capture of dark matter in the Sun by inelastic scattering against nuclei as in the inelastic dark matter scenario. We show that, assuming a WIMP-nucleon cross-section of \\sigma_n = 10^{-40}\\cm^2 the resulting capture rate and density are sufficiently high so that current bounds on the muon neutrino flux from the Sun rule out any appreciable annihilation branching ratio of WIMPs into W^+W^-, Z^0Z^0, \\tau^+\\tau^-, t\\bar{t} and neutrinos. Slightly weaker bounds are also available for annihilations into b\\bar{b} and c\\bar{c}. Annihilations into lighter particles that may produce neutrinos, such as \\mu^+\\mu^-, pions and kaons are unconstrained since those stop in the Sun before decaying. Interestingly enough, this is consistent with some recent proposals motivated by the PAMELA results for the annihilation of WIMPs into light bosons which subsequently decay predominantly into light leptons and pions.

  8. 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.

  9. 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.

  10. 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.

  11. Probing the Small Scale Matter Power Spectrum through Dark Matter Annihilation in the Early Universe

    E-Print Network [OSTI]

    Aravind Natarajan; Nick Zhu; Naoki Yoshida

    2015-03-11

    Recent observations of the cosmic microwave background (CMB) anisotropies and the distribution of galaxies, galaxy clusters, and the Lyman Alpha forest have constrained the shape of the power spectrum of matter fluctuations on large scales k Energy released by dark matter annihilation can modify the spectrum of CMB temperature fluctuations and thus CMB experiments such as Planck have been able to constrain the quantity f /m energy absorbed by gas, is the annihilation rate assumed constant, and m is the particle mass. We assume the standard scale-invariant primordial matter power spectrum of P_prim(k) ~ k^{n_s} at large scales k n_s, the excess small-scale power results in a much larger number of nonlinear small mass halos, particularly at high redshifts. Dark matter annihilation in these halos releases sufficient energy to partially ionize the gas, and consequently modify the spectrum of CMB fluctuations. We show that the recent Planck data can already be used to constrain the power spectrum on small scales. For a simple model with an NFW profile with halo concentration parameter c_200 = 5 and f / m = 1/100 picobarn c / GeV, we can limit the mass variance sigma_{max} < 100 at the 95% confidence level, corresponding to a power law index m_s < 1.43 (1.63) for k_p = 100 (1000) h/Mpc. Our results are also relevant to theories that feature a running spectral index.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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).

  18. 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.

  19. 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.

  20. 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.

  1. Higher order dark matter annihilations in the Sun and implications for IceCube

    SciTech Connect (OSTI)

    Ibarra, Alejandro; Totzauer, Maximilian; Wild, Sebastian E-mail: maximilian.totzauer@mytum.de

    2014-04-01

    Dark matter particles captured in the Sun would annihilate producing a neutrino flux that could be detected at the Earth. In some channels, however, the neutrino flux lies in the MeV range and is thus undetectable at IceCube, namely when the dark matter particles annihilate into e{sup +}e{sup ?}, ?{sup +}?{sup ?} or light quarks. On the other hand, the same interaction that mediates the annihilations into light fermions also leads, via higher order effects, to the production of weak gauge bosons (and in the case of quarks also gluons) that generate a high energy neutrino flux potentially observable at IceCube. We consider in this paper tree level annihilations into a fermion-antifermion pair with the associated emission of one gauge boson and one loop annihilations into two gauge bosons, and we calculate the limits on the scattering cross section of dark matter particles with protons in scenarios where the dark matter particle couples to electrons, muons or light quarks from the non-observation of an excess of neutrino events in the direction of the Sun. We find that the limits on the spin-dependent scattering cross section are, for some scenarios, stronger than the limits from direct detection experiments.

  2. Dark matter relic abundance and big bang nucleosynthesis in Horava's gravity

    SciTech Connect (OSTI)

    Lambiase, G. [University of Salerno (Italy); INFN, Sezione di Napoli (Italy)

    2011-05-15

    The cosmological consequences of Horava's gravity are reviewed in the frameworks of the PAMELA experiment (which has reported an excess of positron events that likely can be ascribed to weakly interacting massive particles dark matter) and of big bang nucleosynthesis. Constraints on parameters characterizing Horawa's cosmology are derived.

  3. 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.

  4. Cold dark matter halos in Multi-coupled Dark Energy cosmologies: structural and statistical properties

    E-Print Network [OSTI]

    Baldi, Marco

    2014-01-01

    The recently proposed Multi-coupled Dark Energy (McDE) scenario - characterised by two distinct Cold Dark Matter (CDM) particle species with opposite couplings to a Dark Energy scalar field - introduces a number of novel features in the small-scale dynamics of cosmic structures, most noticeably the simultaneous existence of both attractive and repulsive fifth-forces. Such small-scale features are expected to imprint possibly observable footprints on nonlinear cosmic structures, that might provide a direct way to test the scenario. In order to unveil such footprints, we have performed the first suite of high-resolution N-body simulations of McDE cosmologies, covering the coupling range $|\\beta |\\leq 1$. We find that for coupling values corresponding to fifth-forces weaker than standard gravity, the impact on structure formation is very mild, thereby showing a new type of screening mechanism for long-range scalar interactions. On the contrary, for fifth-forces comparable to or stronger than standard gravity a n...

  5. CONSTRAINING THE DISTRIBUTION OF DARK MATTER IN THE INNER GALAXY WITH AN INDIRECT DETECTION SIGNAL: THE CASE OF A TENTATIVE 130 GeV {gamma}-RAY LINE

    SciTech Connect (OSTI)

    Yang Ruizhi; Feng Lei; Li Xiang; Fan Yizhong

    2013-06-20

    Dark matter distribution in the very inner region of our Galaxy is still debated. In N-body simulations, a cuspy dark matter halo density profile is favored. Several dissipative baryonic processes, however, are found to be able to significantly flatten dark matter distribution, and a cored dark matter halo density profile is possible. Baryons dominate the gravitational potential in the inner Galaxy, hence a direct constraint on the abundance of dark matter particles is rather challenging. Recently, a few groups have identified a tentative 130 GeV line signal in the Galactic center, which could be interpreted as the signal of dark matter annihilation. Using current 130 GeV line data and adopting the generalized Navarro-Frenk-White profile of the dark matter halo-local dark matter density {rho}{sub 0} = 0.4 GeV cm{sup -3} and r{sub s} = 20 kpc-we obtain a 95% confidence level lower (upper) limit on the inner slope of dark matter density distribution, {alpha} = 1.06 (the cross section of dark matter annihilation into {gamma}-rays ({sigma}v){sub {chi}{chi}{sub {yields}{sub {gamma}{gamma}}}} = 1.3 Multiplication-Sign 10{sup -27} cm{sup 3} s{sup -1}). Such a slope is consistent with the results of some N-body simulations and, if the signal is due to dark matter, suggests that baryonic processes may be unimportant.

  6. 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.

  7. 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 ...

  8. 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 \

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Identifying the Theory of Dark Matter with Direct Detection

    E-Print Network [OSTI]

    Vera Gluscevic; Moira I. Gresham; Samuel D. McDermott; Annika H. G. Peter; Kathryn M. Zurek

    2015-06-15

    Identifying the true theory of dark matter depends crucially on accurately characterizing interactions of dark matter (DM) with other species. In the context of DM direct detection, we present a study of the prospects for correctly identifying the low-energy effective DM-nucleus scattering operators connected to UV-complete models of DM-quark interactions. We take a census of plausible UV-complete interaction models with different low-energy leading-order DM-nuclear responses. For each model (corresponding to different spin-, momentum-, and velocity-dependent responses), we create a large number of realizations of recoil-energy spectra, and use Bayesian methods to investigate the probability that experiments will be able to select the correct scattering model within a broad set of competing scattering hypotheses. We conclude that agnostic analysis of a strong signal (such as Generation-2 would see if cross sections are just below the current limits) seen on xenon and germanium experiments is likely to correctly identify momentum dependence of the dominant response, ruling out models with either "heavy" or "light" mediators, and enabling downselection of allowed models. However, a unique determination of the correct UV completion will critically depend on the availability of measurements from a wider variety of nuclear targets, including iodine or fluorine. We investigate how model-selection prospects depend on the energy window available for the analysis. In addition, we discuss accuracy of the DM particle mass determination under a wide variety of scattering models, and investigate impact of the specific types of particle-physics uncertainties on prospects for model selection.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Dark matter capture in the first stars: a power source and limit on stellar mass

    SciTech Connect (OSTI)

    Freese, Katherine; Spolyar, Douglas; Aguirre, Anthony E-mail: dspolyar@physics.ucsc.edu

    2008-11-15

    The annihilation of weakly interacting massive particles can provide an important heat source for the first (Pop III, 'Pop' standing for 'population') stars, potentially leading to a new phase of stellar evolution known as a 'dark star'. When dark matter (DM) capture via scattering off baryons is included, the luminosity from DM annihilation may dominate over the luminosity due to fusion, depending on the DM density and scattering cross section. The influx of DM due to capture may thus prolong the dark star phase of stellar evolution as long as the ambient DM density is high enough. Comparison of DM luminosity with the Eddington luminosity for the star may constrain the stellar mass of zero-metallicity stars. Alternatively, if sufficiently massive Pop III stars are found, they might be used to bound dark matter properties.

  4. Production of Sterile Neutrino Dark Matter and the 3.5 keV line

    E-Print Network [OSTI]

    Alexander Merle; Aurel Schneider

    2015-02-11

    The recent observation of an X-ray line at an energy of 3.5 keV mainly from galaxy clusters has initiated a discussion about whether we may have seen a possible dark matter signal. If confirmed, this signal could stem from a decaying sterile neutrino of a mass of 7.1 keV. Such a particle could make up all the dark matter, but it is not clear how it was produced in the early Universe. In this letter we show that it is possible to discriminate between different production mechanisms with present-day astronomical data. The most stringent constraint comes from the Lyman-{\\alpha} forest and seems to disfavor all but one of the main production mechanisms proposed in the literature, which is the production via decay of heavy scalar singlets. Pinning down the production mechanism will help to decide whether the X-ray signal indeed comprises an indirect detection of dark matter.

  5. 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.

  6. Investigating dark matter substructure with pulsar timing: II. Improved limits on small-scale cosmology

    E-Print Network [OSTI]

    Hamish A. Clark; Geraint F. Lewis; Pat Scott

    2015-11-19

    Ultracompact Minihalos (UCMHs) have been proposed as a type of dark matter sub-structure seeded by large-amplitude primordial perturbations and topological defects. UCMHs are expected to survive to the present era, allowing constraints to be placed on their cosmic abundance using observations within our own Galaxy. Constraints on their number density can be linked to conditions in the early universe that impact structure formation, such as increased primordial power on small scales, generic weak non-Gaussianity, and the presence of cosmic strings. We use new constraints on the abundance of UCMHs from pulsar timing to place generalised limits on the parameters of each of these cosmological scenarios. At some scales, the limits are the strongest to date, exceeding those from dark matter annihilation. Our new limits have the added advantage of being independent of the particle nature of dark matter, as they are based only on gravitational effects.

  7. Is it possible to explain neutrino masses with scalar dark matter?

    SciTech Connect (OSTI)

    Boehm, Celine [LAPTH, UMR 5108, 9 chemin de Bellevue - BP 110, 74941 Annecy-Le-Vieux (France); Farzan, Yasaman [Institute for Studies in Theoretical Physics and Mathematics (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Hambye, Thomas [Instituto de Fisica Teorica, Universidad Autonoma de Madrid, Cantoblanco (Spain); Palomares-Ruiz, Sergio; Pascoli, Silvia [Institute for Particle Physics Phenomenology, University of Durham, Durham DH1 3LE (United Kingdom)

    2008-02-15

    We present a scenario in which a remarkably simple relation linking dark matter properties and neutrino masses naturally emerges. This framework points towards a low energy theory where the neutrino mass originates from the existence of a light scalar dark matter particle in the keV-MeV mass range. We discuss different ways to constrain and test this scenario by means of astrophysical and cosmological observations as well as laboratory experiments. Finally, we point out that one interesting aspect is that the implied mass range is compatible with the one required for the explanation of the mysterious emission of 511 keV photons from the center of our galaxy in terms of dark matter annihilation into e{sup +}e{sup -} pairs.

  8. Extragalactic Inverse Compton Light from Dark Matter annihilation and the Pamela positron excess

    SciTech Connect (OSTI)

    Profumo, Stefano [Department of Physics, University of California, 1156 High St, Santa Cruz, CA 95064 (United States); Jeltema, Tesla E., E-mail: profumo@scipp.ucsc.edu, E-mail: tesla@ucolick.org [UCO/Lick Observatories, 1156 High St, Santa Cruz, CA 95064 (United States)

    2009-07-01

    We calculate the extragalactic diffuse emission originating from the up-scattering of cosmic microwave photons by energetic electrons and positrons produced in particle dark matter annihilation events at all redshifts and in all halos. We outline the observational constraints on this emission and we study its dependence on both the particle dark matter model (including the particle mass and its dominant annihilation final state) and on assumptions on structure formation and on the density profile of halos. We find that for low-mass dark matter models, data in the X-ray band provide the most stringent constraints, while the gamma-ray energy range probes models featuring large masses and pair-annihilation rates, and a hard spectrum for the injected electrons and positrons. Specifically, we point out that the all-redshift, all-halo inverse Compton emission from many dark matter models that might provide an explanation to the anomalous positron fraction measured by the Pamela payload severely overproduces the observed extragalactic gamma-ray background.

  9. Dark-matter bound states from Feynman diagrams

    E-Print Network [OSTI]

    Petraki, Kalliopi; Wiechers, Michael

    2015-01-01

    If dark matter couples directly to a light force mediator, then it may form bound states in the early universe and in the non-relativistic environment of haloes today. In this work, we establish a field-theoretic framework for the computation of bound-state formation cross-sections, de-excitation and decay rates, in theories with long-range interactions. Using this formalism, we carry out specific computations for scalar particles interacting either via a light scalar or vector mediator. At low relative velocities of the interacting particles, the formation of bound states is enhanced by the Sommerfeld effect. For particle-antiparticle pairs, we show that bound-state formation can be faster than annihilation into radiation in the regime where the Sommerfeld effect is important. The field-theoretic formalism outlined here can be generalised to compute bound-state formation cross-sections in a variety of theories, including theories featuring non-Abelian (albeit non-confining) interactions, such as the electrow...

  10. Dark-matter bound states from Feynman diagrams

    E-Print Network [OSTI]

    Kalliopi Petraki; Marieke Postma; Michael Wiechers

    2015-06-26

    If dark matter couples directly to a light force mediator, then it may form bound states in the early universe and in the non-relativistic environment of haloes today. In this work, we establish a field-theoretic framework for the computation of bound-state formation cross-sections, de-excitation and decay rates, in theories with long-range interactions. Using this formalism, we carry out specific computations for scalar particles interacting either via a light scalar or vector mediator. At low relative velocities of the interacting particles, the formation of bound states is enhanced by the Sommerfeld effect. For particle-antiparticle pairs, we show that bound-state formation can be faster than annihilation into radiation in the regime where the Sommerfeld effect is important. The field-theoretic formalism outlined here can be generalised to compute bound-state formation cross-sections in a variety of theories, including theories featuring non-Abelian (albeit non-confining) interactions, such as the electroweak interactions.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. The case for mixed dark matter from sterile neutrinos

    E-Print Network [OSTI]

    Louis Lello; Daniel Boyanovsky

    2015-08-17

    Sterile neutrinos are $SU(2)$ singlets that mix with active neutrinos via a mass matrix, its diagonalization leads to mass eigenstates that couple via standard model vertices. We study the cosmological production of heavy neutrinos via \\emph{standard model charged and neutral current vertices} under a minimal set of assumptions: i) the mass basis contains a hierarchy of heavy neutrinos, ii) these have very small mixing angles with the active (flavor) neutrinos, iii) standard model particles, including light (active-like) neutrinos are in thermal equilibrium. If kinematically allowed, the same weak interaction processes that produce active-like neutrinos also produce the heavier species. We introduce the quantum kinetic equations that describe their production, freeze out and decay and discuss the various processes that lead to their production in a wide range of temperatures assessing their feasibility as dark matter candidates. We identify processes in which finite temperature collective excitations may lead to the production of the heavy species. As a specific example, we consider the production of heavy neutrinos in the mass range $M_h \\lesssim 140 \\,\\mathrm{MeV}$ from pion decay shortly after the QCD crossover including finite temperature corrections to the pion form factors and mass. We consider the different decay channels that allow for the production of heavy neutrinos showing that their frozen distribution functions exhibit effects from "kinematic entanglement" and argue for their viability as mixed dark matter candidates. We discuss abundance, phase space density and stability constraints and argue that heavy neutrinos with lifetime $\\tau> 1/H_0$ freeze out of local thermal equilibrium, and \\emph{conjecture} that those with lifetimes $\\tau \\ll 1/H_0$ may undergo cascade decay into lighter DM candidates and/or inject non-LTE neutrinos into the cosmic neutrino background.

  16. Looking for Dark Matter through the Bottom of a Wine Glass!

    E-Print Network [OSTI]

    Collar, Juan I.

    , and detect the imprint of dark energy on the web of dark matter that winds across the cosmos. Café Email listLooking for Dark Matter through the Bottom of a Wine Glass! (IYA Strange Telescope Series://cfcpwork.uchicago.edu/mailman/listinfo/cafe! #12;Looking for Dark Matter through the Bottom of a Wine Glass! (IYA Strange Telescope Series

  17. Dark Matter, Mass Scales Sequence, and Superstructure in the Universe (with extension)

    E-Print Network [OSTI]

    Wuliang Huang; Xiaodong Huang

    2015-10-26

    There is a category of stable non-baryonic dark matter particles in the universe at the present time: fermions or bosons with mass ~10^(-1) eV. The existence of these do not contradict the dip phenomena of the ultra-high energy primary cosmic ray spectrum at ~10^(15) eV ("knee") and ~10^(18) eV ("ankle"), nor the existence of galaxies at large red shift z~10. The mass scales sequence connected by a large number A, especially the superstructure scale, is helpful in the understanding of the Hubble constant and the cosmological constant. The second section (extension section) of this paper describes the extension of the mass scales sequence and new particles (u-particle, Planck particle, A-particle, delta-particle...). This can be used to explore the state of matter with super-high density (much greater than nuclear density), inflation, lightest black hole (LBH) etc in the early universe. The inflation appears as a step by step fission process of black holes. Measuring the rate of change of the speed of light and the Planck constant h at the present time year after year is an important step. Doing so can check whether the cosmological constant exists. The third section of this paper is a summary. That describes and reviews the large number, the mass scales sequence, background particles, the evolution of the universe, critical energy, renormalization, and beyond SM (dark matter particles with low mass), especially for the finite universe.

  18. 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.

  19. Inflation, baryogenesis and gravitino dark matter at ultra low reheat temperatures

    E-Print Network [OSTI]

    Kazunori Kohri; Anupam Mazumdar; Narendra Sahu

    2009-05-11

    It is quite possible that the reheat temperature of the universe is extremely low close to the scale of Big Bang nucleosynthesis, i.e. $T_{R}\\sim 1-10$ MeV. At such low reheat temperatures generating matter anti-matter asymmetry and synthesizing dark matter particles are challenging issues which need to be addressed within a framework of beyond the Standard Model physics. In this paper we point out that a successful cosmology can emerge naturally provided the R-parity violating interactions are responsible for the excess in baryons over anti-baryons and at the same time they can explain the longevity of dark matter with the right abundance.

  20. At the heart of the matter: the origin of bulgeless dwarf galaxies and Dark Matter cores

    E-Print Network [OSTI]

    Fabio Governato; Chris Brook; Lucio Mayer; Alyson Brooks; George Rhee; James Wadsley; Patrik Jonsson; Beth Willman; Greg Stinson; Thomas Quinn; Piero Madau

    2009-11-11

    For almost two decades the properties of "dwarf" galaxies have challenged the Cold Dark Matter (CDM) paradigm of galaxy formation. Most observed dwarf galaxies consists of a rotating stellar disc embedded in a massive DM halo with a near constant-density core. Yet, models based on the CDM scenario invariably form galaxies with dense spheroidal stellar "bulges" and steep central DM profiles, as low angular momentum baryons and DM sink to the center of galaxies through accretion and repeated mergers. Processes that decrease the central density of CDM halos have been identified, but have not yet reconciled theory with observations of present day dwarfs. This failure is potentially catastrophic for the CDM model, possibly requiring a different DM particle candidate. This Letter presents new hydrodynamical simulations in a Lambda$CDM framework where analogues of dwarf galaxies, bulgeless and with a shallow central DM profile, are formed. This is achieved by resolving the inhomogeneous interstellar medium, resulting in strong outflows from supernovae explosions which remove low angular momentum gas. This inhibits the formation of bulges and decreases the dark-matter density to less than half within the central kiloparsec. Realistic dwarf galaxies are thus shown to be a natural outcome of galaxy formation in the CDM scenario.

  1. Dark Matter and Dark Energy from the solution of the strong CP problem

    E-Print Network [OSTI]

    Roberto Mainini; Silvio A. Bonometto

    2004-07-19

    The Peccei Quinn (PQ) solution of the strong CP problem requires the existence of axions, which are a viable candidate for Dark Matter. Here we show that, if the Nambu Goldstone potential of the PQ model is replaced by a potential V(|\\Phi|) admitting a tracker solution, the scalar field |\\Phi| can account for Dark Energy, while the phase of \\Phi yields axion Dark Matter. Such Dark Matter and Dark Energy turn out to be weakly coupled. If V is a SUGRA potential, the model essentially depends on a single parameter, the energy scale \\Lambda. Once we set \\Lambda \\simeq 10^{10} GeV, at the quark--hadron transition, |\\Phi| naturally passes through values suitable to solve the strong CP problem, later growing to values providing fair amounts of Dark Matter and Dark Energy. In this model, the linear growth factor, from recombination to now, is quite close to \\LambdaCDM. The selected \\Lambda value can be an indication of the scale where the soft breaking of SUSY occurred.

  2. On Einstein - Weyl unified model of dark energy and dark matter

    E-Print Network [OSTI]

    A. T. Filippov

    2009-05-29

    Here I give a more detailed account of the part of the conference report that was devoted to reinterpreting the Einstein `unified models of gravity and electromagnetism' (1923) as the unified theory of dark energy (cosmological constant) and dark matter (neutral massive vector particle having only gravitational interactions). After summarizing Einstein's work and related earlier work of Weyl and Eddington, I present an approach to finding spherically symmetric solutions of the simplest variant of the Einstein models that was earlier mentioned in Weyl's work as an example of his generalization of general relativity. The spherically symmetric static solutions and homogeneous cosmological models are considered in some detail. As the theory is not integrable we study approximate solutions. In the static case, we show that there may exist two horizons and derive solutions near horizons. In cosmology, we propose to study the corresponding expansions of possible solutions near the origin and derive these expansions in a simplified model neglecting anisotropy. The structure of the solutions seems to hint at a possibility of an inflation mechanism that does not require adding scalar fields.

  3. Coincidences of Dark Energy with Dark Matter -- Clues for a Simple Alternative?

    E-Print Network [OSTI]

    HongSheng Zhao

    2007-10-21

    A rare coincidence of scales in standard particle physics is needed to explain why $\\Lambda$ or the negative pressure of cosmological dark energy (DE) coincides with the positive pressure $P_0$ of random motion of dark matter (DM) in bright galaxies. Recently Zlosnik et al. (2007) propose to modify the Einsteinian curvature by adding a non-linear pressure from a medium flowing with a four-velocity vector field $U^\\mu$. We propose to check whether a smooth extension of GR with a simple kinetic Lagrangian of $U^\\mu$ can be constructed, and whether the pressure can bend space-time sufficiently to replace the roles of a $w=-1$ DE, $w=0$ Cold DM and heavy neutrinos in explaining anomalous accelerations at all scales. As a specific proof of concept we find a Vector-for-$\\Lambda$ model (${\\mathbf V\\Lambda}$-model) and its variants. With essentially {\\it no free parameters}, these appear broadly consistent with the solar system, gravitational potentials in dwarf spiral galaxies and the bullet cluster of galaxies, early universe with inflation, structure formation and BBN, and late acceleration with a 1:3 ratio of DM:DE.

  4. Coincidences of Dark Energy with Dark Matter -- Clues for a Simple Alternative?

    E-Print Network [OSTI]

    Zhao, HongSheng

    2007-01-01

    A rare coincidence of scales in standard particle physics is needed to explain why $\\Lambda$ or the negative pressure of cosmological dark energy (DE) coincides with the positive pressure $P_0$ of random motion of dark matter (DM) in bright galaxies. Recently Zlosnik et al. (2007) propose to modify the Einsteinian curvature by adding a non-linear pressure from a medium flowing with a four-velocity vector field $U^\\mu$. We propose to check whether a smooth extension of GR with a simple kinetic Lagrangian of $U^\\mu$ can be constructed, and whether the pressure can bend space-time sufficiently to replace the roles of a $w=-1$ DE, $w=0$ Cold DM and heavy neutrinos in explaining anomalous accelerations at all scales. As a specific proof of concept we find a Vector-for-$\\Lambda$ model (${\\mathbf V\\Lambda}$-model) and its variants. With essentially {\\it no free parameters}, these appear broadly consistent with the solar system, gravitational potentials in dwarf spiral galaxies and the bullet cluster of galaxies, ear...

  5. 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.

  6. 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

  7. Testing MONDian dark matter with galactic rotation curves

    SciTech Connect (OSTI)

    Edmonds, Doug [Department of Physics, Emory and Henry College, Emory, VA 24327 (United States); Farrah, Duncan; Minic, Djordje; Takeuchi, Tatsu [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Ho, Chiu Man [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Ng, Y. Jack, E-mail: dedmonds@ehc.edu, E-mail: farrah@vt.edu, E-mail: dminic@vt.edu, E-mail: takeuchi@vt.edu, E-mail: chiuman.ho@vanderbilt.edu, E-mail: yjng@physics.unc.edu [Institute of Field Physics, Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2014-09-20

    MONDian dark matter (MDM) is a new form of dark matter quantum that naturally accounts for Milgrom's scaling, usually associated with modified Newtonian dynamics (MOND), and theoretically behaves like cold dark matter (CDM) at cluster and cosmic scales. In this paper, we provide the first observational test of MDM by fitting rotation curves to a sample of 30 local spiral galaxies (z ? 0.003). For comparison, we also fit the galactic rotation curves using MOND and CDM. We find that all three models fit the data well. The rotation curves predicted by MDM and MOND are virtually indistinguishable over the range of observed radii (?1 to 30 kpc). The best-fit MDM and CDM density profiles are compared. We also compare with MDM the dark matter density profiles arising from MOND if Milgrom's formula is interpreted as Newtonian gravity with an extra source term instead of as a modification of inertia. We find that discrepancies between MDM and MOND will occur near the center of a typical spiral galaxy. In these regions, instead of continuing to rise sharply, the MDM mass density turns over and drops as we approach the center of the galaxy. Our results show that MDM, which restricts the nature of the dark matter quantum by accounting for Milgrom's scaling, accurately reproduces observed rotation curves.

  8. Higgs Inflation, Seesaw Physics and Fermion Dark Matter

    E-Print Network [OSTI]

    Nobuchika Okada; Qaisar Shafi

    2015-01-22

    We present an inflationary model in which the Standard Model Higgs doublet field with non-minimal coupling to gravity drives inflation, and the effective Higgs potential is stabilized by new physics which includes a dark matter particle and right-handed neutrinos for the seesaw mechanism. All of the new particles are fermions, so that the Higgs doublet is the unique inflaton candidate. With central values for the masses of the top quark and the Higgs boson, the renormalization group improved Higgs potential is employed to yield the scalar spectral index $n_s \\simeq 0.968$, the tensor-to-scalar ratio $r \\simeq 0.003$, and the running of the spectral index $\\alpha=dn_s/d \\ln k \\simeq -5.2 \\times 10^{-4}$ for the number of e-folds $N_0=60$ ($n_s \\simeq 0.962$, $r \\simeq 0.004$, and $\\alpha \\simeq -7.5 \\times 10^{-4}$ for $N_0=50$). The fairly low value of $r \\simeq 0.003$ predicted in this class of models means that the ongoing space and land based experiments are not expected to observe gravity waves generated during inflation. [Dedicated to the memory of Dr. Paul Weber (1947 - 2015). Paul was an exceptional human being and a very special friend who will be sorely missed.

  9. Testing MeV dark matter with neutrino detectors

    SciTech Connect (OSTI)

    Palomares-Ruiz, Sergio; Pascoli, Silvia [IPPP, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)

    2008-01-15

    MeV particles have been advocated as dark matter (DM) candidates in different contexts. This hypothesis can be tested indirectly by searching for the standard model (SM) products of DM self-annihilations. As the signal from DM self-annihilations depends on the square of the DM density, we might expect a sizable flux of annihilation products from our galaxy. Neutrinos are the least detectable particles in the SM and a null signal in this channel would allow to set the most conservative bound on the total annihilation cross section. Here, we show that neutrino detectors with good energy resolution and low energy thresholds can not only set bounds on the annihilation cross section but actually test the hypothesis of the possible existence of MeV DM, i.e. test the values of the cross section required to explain the observed DM density. At present, the data in the (positron) energy interval [18-82] MeV of the Super-Kamiokande experiment is already able to put a very stringent bound on the annihilation cross section for masses between {approx}15-130 MeV. Future large experiments, like megaton water-Cerenkov or large scintillator detectors, will improve the present limits and, if MeV DM exists, would be able to detect it.

  10. 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/\

  11. Dark matter effective field theory scattering in direct detection experiments

    E-Print Network [OSTI]

    K. Schneck; B. Cabrera; D. G. Cerdeno; V. Mandic; H. E. Rogers; R. Agnese; A. J. Anderson; M. Asai; D. Balakishiyeva; D. Barker; R. Basu Thakur; D. A. Bauer; J. Billard; A. Borgland; D. Brandt; P. L. Brink; R. Bunker; D. O. Caldwell; R. Calkins; H. Chagani; Y. Chen; J. Cooley; B. Cornell; C. H. Crewdson; P. Cushman; M. Daal; P. C. F. Di Stefano; T. Doughty; L. Esteban; S. Fallows; E. Figueroa-Feliciano; G. L. Godfrey; S. R. Golwala; J. Hall; H. R. Harris; T. Hofer; D. Holmgren; L. Hsu; M. E. Huber; D. M. Jardin; A. Jastram; O. Kamaev; B. Kara; M. H. Kelsey; A. Kennedy; A. Leder; B. Loer; E. Lopez Asamar; P. Lukens; R. Mahapatra; K. A. McCarthy; N. Mirabolfathi; R. A. Moffatt; J. D. Morales Mendoza; S. M. Oser; K. Page; W. A. Page; R. Partridge; M. Pepin; A. Phipps; K. Prasad; M. Pyle; H. Qiu; W. Rau; P. Redl; A. Reisetter; Y. Ricci; A. Roberts; T. Saab; B. Sadoulet; J. Sander; R. W. Schnee; S. Scorza; B. Serfass; B. Shank; D. Speller; D. Toback; S. Upadhyayula; A. N. Villano; B. Welliver; J. S. Wilson; D. H. Wright; X. Yang; S. Yellin; J. J. Yen; B. A. Young; J. Zhang

    2015-06-22

    We examine the consequences of the effective field theory (EFT) of dark matter-nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  12. Right-handed Neutrinos as Superheavy Dark Matter

    E-Print Network [OSTI]

    Yosuke Uehara

    2002-01-04

    We propose that right-handed neutrinos are very long-lived dark matter. The long lifetime is realized by the separation of the wavefunction of right-handed neutrinos and that of other fermions in an extra dimension. Such long-lived and superheavy dark matter can naturally explain observed ultra high energy cosmic rays above the GZK cutoff (5 * 10^{19} eV) and huge amounts of cold dark matter simultaneously. Furthermore, the exponentially suppressed Yukawa couplings of right-handed neutrinos leads to the high predictablilty on the mass parameter of the neutrinoless double beta decay, as all the models which predict very small neutrino mass of one generation.

  13. Stable Higgs Bosons - new candidate for cold dark matter -

    E-Print Network [OSTI]

    Yutaka Hosotani

    2010-03-31

    The Higgs boson is in the backbone of the standard model of electroweak interactions. It must exist in some form for achieving unification of interactions. In the gauge-Higgs unification scenario the Higgs boson becomes a part of the extra-dimensional component of gauge fields. The Higgs boson becomes absolutely stable in a class of the gauge-Higgs unification models, serving as a promising candidate for cold dark matter in the universe. The observed relic abundance of cold dark matter is obtained with the Higgs mass around 70 GeV. The Higgs-nucleon scattering cross section is found to be close to the recent CDMS II and XENON10 bounds in the direct detection of dark matter. In collider experiments stable Higgs bosons are produced in a pair, appearing as missing energies and momenta so that the way of detecting Higgs bosons must be altered.

  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. Directional Dark Matter Detection Beyond the Neutrino Bound

    E-Print Network [OSTI]

    Philipp Grothaus; Malcolm Fairbairn; Jocelyn Monroe

    2014-09-30

    Coherent scattering of solar, atmospheric and diffuse supernovae neutrinos creates an irreducible background for direct dark matter experiments with sensitivities to WIMP-nucleon spin-independent scattering cross-sections of 10^(-46)-10^(-48) cm^2, depending on the WIMP mass. Even if one could eliminate all other backgrounds, this "neutrino floor" will limit future experiments with projected sensitivities to cross-sections as small as 10^(-48) cm^2. Direction-sensitive detectors have the potential to study dark matter beyond the neutrino bound by fitting event distributions in multiple dimensions: recoil kinetic energy, recoil track angle with respect to the sun, and event time. This work quantitatively explores the impact of direction-sensitivity on the neutrino bound in dark matter direct detection.

  16. The dark matter is mostly an axion BEC

    E-Print Network [OSTI]

    Sikivie, Pierre

    2010-01-01

    Axions differ from ordinary cold dark matter, such as WIMPs or sterile neutrinos, because they form a Bose-Einstein condensate (BEC). As a result, axions accreting onto a galactic halo fall in with net overall rotation. In contrast, ordinary CDM accretes onto galactic halos with an irrotational velocity field. The inner caustics are different in the two cases. It is shown that if the dark matter is axions, the phase space structure of the halos of isolated disk galaxies, such as the Milky Way, is precisely that of the caustic ring model for which observational support exists. The other dark matter candidates predict a far more chaotic phase space structure for galactic halos.

  17. Declarative Modeling and Bayesian Inference of Dark Matter Halos

    E-Print Network [OSTI]

    Kronberger, Gabriel

    2013-01-01

    Probabilistic programming allows specification of probabilistic models in a declarative manner. Recently, several new software systems and languages for probabilistic programming have been developed on the basis of newly developed and improved methods for approximate inference in probabilistic models. In this contribution a probabilistic model for an idealized dark matter localization problem is described. We first derive the probabilistic model for the inference of dark matter locations and masses, and then show how this model can be implemented using BUGS and Infer.NET, two software systems for probabilistic programming. Finally, the different capabilities of both systems are discussed. The presented dark matter model includes mainly non-conjugate factors, thus, it is difficult to implement this model with Infer.NET.

  18. Isospin-Violating Dark Matter and Neutrinos From the Sun

    E-Print Network [OSTI]

    Shao-Long Chen; Yue Zhang

    2011-06-20

    We study the indirect detection of dark matter through neutrino flux from their annihilation in the center of the Sun, in a class of theories where the dark matter-nucleon spin-independent interactions break the isospin symmetry. We point out that, while the direct detection bounds with heavy targets like Xenon are weakened and reconciled with the positive signals in DAMA and CoGeNT experiments, the indirect detection using neutrino telescopes can impose a relatively stronger constraint and brings tension to such explanation, if the annihilation is dominated by heavy quark or $\\tau$-lepton final states. As a consequence, the qualified isospin violating dark matter candidate has to preferably annihilate into light flavors.

  19. 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.

  20. 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.

  1. Regular black hole remnants and graviatoms with de Sitter interior as heavy dark matter candidates probing inhomogeneity of early universe

    E-Print Network [OSTI]

    Dymnikova, Irina

    2015-01-01

    We address the question of regular primordial black holes with de Sitter interior, their remnants and gravitational vacuum solitons G-lumps as heavy dark matter candidates providing signatures for inhomogeneity of early universe, which is severely constrained by the condition that the contribution of these objects in the modern density does not exceed the total density of dark matter. Primordial black holes and their remnants seem to be most elusive among dark matter candidates. However, we reveal a nontrivial property of compact objects with de Sitter interior to induce proton decay or decay of neutrons in neutron stars. The point is that they can form graviatoms, binding electrically charged particles. Their observational signatures as dark matter candidates provide also signatures for inhomogeneity of the early universe. In graviatoms, the cross-section of the induced proton decay is strongly enhanced, what provides the possibility of their experimental searches. We predict proton decay paths induced by gr...

  2. The prolate dark matter halo of the Andromeda galaxy

    SciTech Connect (OSTI)

    Hayashi, Kohei; Chiba, Masashi E-mail: chiba@astr.tohoku.ac.jp

    2014-07-01

    We present new limits on the global shape of the dark matter halo in the Andromeda galaxy using and generalizing non-spherical mass models developed by Hayashi and Chiba and compare our results with theoretical predictions of cold dark matter (CDM) models. This is motivated by the fact that CDM models predict non-spherical virialized dark halos, which reflect the process of mass assembly in the galactic scale. Applying our models to the latest kinematic data of globular clusters and dwarf spheroidal galaxies in the Andromeda halo, we find that the most plausible cases for Andromeda yield a prolate shape for its dark halo, irrespective of assumed density profiles. We also find that this prolate dark halo in Andromeda is consistent with theoretical predictions in which the satellites are distributed anisotropically and preferentially located along major axes of their host halos. It is a reflection of the intimate connection between galactic dark matter halos and the cosmic web. Therefore, our result is profound in understanding internal dynamics of halo tracers in Andromeda, such as orbital evolutions of tidal stellar streams, which play important roles in extracting the abundance of CDM subhalos through their dynamical effects on stream structures.

  3. 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.

  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. 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.

  6. The Hubble Web: The Dark Matter Problem and Cosmic Strings

    E-Print Network [OSTI]

    Stephon Alexander

    2007-02-27

    I propose a reinterpretation of cosmic dark matter in which a rigid network of cosmic strings formed at the end of inflation. The cosmic strings fulfill three functions: At recombination they provide an accretion mechanism for virializing baryonic and warm dark matter into disks. These cosmic strings survive as configurations which thread spiral and elliptical galaxies leading to the observed flatness of rotation curves and the Tully-Fisher relation. We find a relationship between the rotational velocity of the galaxy and the string tension and discuss the testability of this model.

  7. The Hubble Web: The Dark Matter Problem and Cosmic Strings

    SciTech Connect (OSTI)

    Alexander, Stephon

    2009-07-06

    I propose a reinterpretation of cosmic dark matter in which a rigid network of cosmic strings formed at the end of inflation. The cosmic strings fulfill three functions: At recombination they provide an accretion mechanism for virializing baryonic and warm dark matter into disks. These cosmic strings survive as configurations which thread spiral and elliptical galaxies leading to the observed flatness of rotation curves and the Tully-Fisher relation. We find a relationship between the rotational velocity of the galaxy and the string tension and discuss the testability of this model.

  8. 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.

  9. The First Billion Years of a Warm Dark Matter Universe

    E-Print Network [OSTI]

    Maio, Umberto

    2014-01-01

    We present results of cosmological N-body hydrodynamic chemistry simulations of primordial structure growth and evolution in a scenario with warm dark matter (WDM) having a mass of 3keV and compare with a model consisting of standard cold dark matter (CDM). We focus on the high-redshift universe ($z>6$), where the structure formation process should better reflect the primordial (linear) differences in terms of matter power spectrum. We find that early epochs are exceptional probes of the dark-matter nature. Non-linear CDM and WDM power spectra differ by up to 2 dex at early times and show spreads of factor of a few persisting in the whole first Gyr. Primordial WDM objects with masses $\\lesssim 10^8\\,\\rm M_\\odot$ are less abundant by $\\gtrsim 1\\,\\rm dex$, both in terms of dark matter and of baryon content. Runaway molecular cooling in primordial WDM mini-haloes results severely inhibited due to the damping of power at large $k$ modes. As a consequence, the cosmic (population III and II-I) star formation activi...

  10. DARK MATTER HEATING AND EARLY CORE FORMATION IN DWARF GALAXIES

    SciTech Connect (OSTI)

    Madau, Piero; Shen, Sijing [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Governato, Fabio [Astronomy Department, University of Washington, Seattle, WA 98195 (United States)

    2014-07-01

    We present more results from a fully cosmological ?CDM simulation of a group of isolated dwarf galaxies that has been shown to reproduce the observed stellar mass and cold gas content, resolved star formation histories, and metallicities of dwarfs in the Local Volume. Here we investigate the energetics and timetable of the cusp-core transformation. As suggested by previous work, supernova-driven gas outflows remove dark matter (DM) cusps and create kiloparsec-size cores in all systems having a stellar mass M {sub *} > 10{sup 6} M {sub ?}. The {sup D}M core mass removal efficiency{sup —}dark mass ejected per unit stellar mass—ranges today from a few to a dozen, and increases with decreasing host mass. Because dwarfs form the bulk of their stars prior to redshift 1 and the amount of work required for DM heating and core formation scales approximately as M{sub vir}{sup 5/3}, the unbinding of the DM cusp starts early and the formation of cored profiles is not as energetically onerous as previously claimed. DM particles in the cusp typically migrate to 2-3 core radii after absorbing a few percent of the energy released by supernovae. The present-day slopes of the inner DM mass profiles, ? ? dlog M/dlog R ? 2.5-3, of the simulated ''Bashful'' and ''Doc'' dwarfs are similar to those measured in the luminous Fornax and Sculptor dwarf spheroidals. None of the simulated galaxies has a circular velocity profile exceeding 20 km s{sup –1} in the inner 1 kpc, implying that supernova feedback is key to solve the ''too-big-to-fail'' problem for Milky Way subhalos.

  11. Constraining scalar dark matter with Big Bang nucleosynthesis and atomic spectroscopy

    E-Print Network [OSTI]

    Stadnik, Y V

    2015-01-01

    Scalar dark matter can interact with Standard Model (SM) particles, altering the fundamental constants of Nature in the process. Changes in the fundamental constants during and before Big Bang nucleosynthesis (BBN) produce changes in the primordial abundances of the light elements. In particular, the primordial abundance of $^{4}$He is predominantly determined by the ratio of the neutron-proton mass difference to freeze-out temperature at the time of the weak interaction freeze-out prior to BBN, which is a sensitive function of the fundamental constants. By comparing the measured and calculated (within the SM) primordial abundance of $^{4}$He, we are able to derive stringent constraints on the mass of a scalar dark matter particle $\\phi$ together with its interactions with photons, light quarks and massive vector bosons via linear and quadratic couplings in $\\phi$. We also derive constraints on the quadratic interaction of $\\phi$ with photons from recent atomic dysprosium spectroscopy measurements.

  12. Constraining scalar dark matter with Big Bang nucleosynthesis and atomic spectroscopy

    E-Print Network [OSTI]

    Y. V. Stadnik; V. V. Flambaum

    2015-04-12

    Scalar dark matter can interact with Standard Model (SM) particles, altering the fundamental constants of Nature in the process. Changes in the fundamental constants during and prior to Big Bang nucleosynthesis (BBN) produce changes in the primordial abundances of the light elements. By comparing the measured and calculated (within the SM) primordial abundance of $^{4}$He, which is predominantly determined by the ratio of the neutron-proton mass difference to freeze-out temperature at the time of weak interaction freeze-out prior to BBN, we are able to derive stringent constraints on the mass of a scalar dark matter particle $\\phi$ together with its interactions with the photon, light quarks and massive vector bosons via quadratic couplings in $\\phi$, as well as its interactions with massive vector bosons via linear couplings in $\\phi$. We also derive a stringent constraint on the quadratic interaction of $\\phi$ with the photon from recent atomic dysprosium spectroscopy measurements.

  13. Hydro-gravitational fragmentation, diffusion and condensation of the primordial plasma, dark-matter and gas

    E-Print Network [OSTI]

    Carl H. Gibson

    2003-05-19

    The first structures were proto-voids formed in the primordial plasma. Viscous and weak turbulence forces balanced gravitational forces when the scale of causal connection at time 30,000 years matched the viscous and turbulent Schwarz scales of hydro-gravitational theory (Gibson 1996). The photon viscosity allows only weak turbulence from the Reynolds number Re = 200, with fragmentation to give proto-supercluster voids, buoyancy forces, fossil vorticity turbulence, and strong sonic damping. The expanding, cooling, plasma continued fragmentation to proto-galaxy-mass with the density and rate-of-strain preserved as fossils of the weak turbulence and first structure. Turbulence fossilization by self-gravitational buoyancy explains the cosmic microwave background temperature fluctuations, not sonic oscillations in cold-dark-matter fragments. After plasma to gas transition at 300,000 years, gas fragmentation occurred within the proto-galaxies to form proto-globular-star-cluster (PGCs) clouds of small-planetary-mass primordial-fog-particles (PFPs). Dark PGC clumps of frozen PFPs persist as the inner-galaxy-halo dark matter, supporting Schild's 1996 quasar-microlensing interpretation. Non-baryonic dark matter diffused into the plasma proto-cluster-voids and later fragmented as outer-galaxy-halos at diffusive Schwarz scales, indicating light, weakly-collisional fluid particles (possibly neutrinos). Observations support the theory (Gibson and Schild 2003).

  14. Characteristic Size and Mass of Galaxies in the Bose-Einstein Condensate Dark Matter Model

    E-Print Network [OSTI]

    Lee, Jae-Weon

    2015-01-01

    We study an inherent length scale of galactic halos in the Bose-Einstein condensate (or scalar field) dark matter model. Considering evolution of the density perturbation we show that the average background matter density determines a quantum Jeans mass and hence the spatial size of galaxies. In this model the minimum size of galaxies increases, while the minimum mass of the galaxies decreases as the universe evolves. The observed values of the mass and the size of the dwarf galaxies are successfully reproduced with the dark matter particle mass $m\\simeq 5\\times 10^{-22}eV$. The rotation velocity of dwarf galaxies is $O(\\sqrt{H/m}$) c, where $H$ is the Hubble parameter. We also suggest that ultra compact dwarf galaxies are remnants of dwarf galaxies formed in the early universe.

  15. 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...

  16. 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...

  17. The case for a directional dark matter detector and the status of current experimental efforts

    E-Print Network [OSTI]

    Battat, James

    We present the case for a dark matter detector with directional sensitivity. This document was developed at the 2009 CYGNUS workshop on directional dark matter detection, and contains contributions from theorists and ...

  18. 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 ...

  19. Dark Matter phenomenology of intersecting D6-branes with a Stueckelberg portal

    E-Print Network [OSTI]

    Victor Martin-Lozano

    2015-10-12

    We discuss the possibility that a Stueckelberg portal connects both Standard Model and Dark Matter sectors. The particle responsible of this portal is the lightest Z' boson that induces isospin-violating interactions. This property leads to a rich phenomenology for the direct detection and collider experiments that can constraint the parameter space of this kind of models and can be tested in the future.

  20. The Anisotropy of the Extragalactic Radio Background from Dark Matter Annihilation

    E-Print Network [OSTI]

    Ke Fang; Tim Linden

    2014-12-23

    Observations of the extragalactic radio background have uncovered a significant isotropic emission across multiple frequencies spanning from 22 MHz to 10 GHz. The intensity of this non-thermal emission component significantly exceeds the expected contribution from known astrophysical sources. Interestingly, models have indicated that the annihilation of dark matter particles may reproduce both the flux and spectrum of the excess. However, the lack of a measurable anisotropy in the residual emission remains challenging for both dark matter and standard astrophysical interpretations of the ARCADE-2 data. We calculate the expected synchrotron anisotropy from dark matter annihilation and show that these models can produce very small anisotropies, though this requires galaxy clusters to have large substructure contributions and strong magnetic fields. We show that this constraint can be significantly relaxed, however, in scenarios where electrons produced via dark matter annihilation can be efficiently reaccelerated by Alfv\\'en waves in the intra-Cluster medium. Our analysis indicates that any source capable of explaining the intensity and isotropy of the extragalactic radio excess must have a spatial extension far larger than typical for baryons in galaxies, suggesting a novel physics interpretation.

  1. Investigating dark matter substructure with pulsar timing: I. Constraints on ultracompact minihalos

    E-Print Network [OSTI]

    Hamish A. Clark; Geraint F. Lewis; Pat Scott

    2015-11-19

    Small-scale dark matter structure within the Milky Way is expected to affect pulsar timing. The change in gravitational potential induced by a dark matter halo passing near the line of sight to a pulsar would produce a varying delay in the light travel time of photons from the pulsar. Individual transits produce an effect that would either be too rare or too weak to be detected in 30-year pulsar observations. However, a population of dark matter subhalos would be expected to produce a detectable effect on the measured properties of pulsars if the subhalos constitute a significant fraction of the total halo mass. The effect is to increase the dispersion of measured period derivatives across the pulsar population. By statistical analysis of the ATNF pulsar catalogue, we place an upper limit on this dispersion of $\\log \\sigma_{\\dot{P}} \\leq -17.05$. We use this to place strong upper limits on the number density of ultracompact minihalos within the Milky Way. These limits are completely independent of the particle nature of dark matter.

  2. Dynamics of a scalar field, with a double exponential potential, interacting with dark matter

    E-Print Network [OSTI]

    Vartika Gupta; Rakesh Kabir; Amitabha Mukherjee; Daksh Lohiya

    2015-01-15

    We study the interaction between dark matter and dark energy, with dark energy described by a scalar field having a double exponential effective potential. We discover conditions under which such a scalar field driven solution is a late time attractor. We observe a realistic cosmological evolution which consists of sequential stages of dominance of radiation, matter and dark energy, respectively.

  3. Hidden sector monopole, vector dark matter and dark radiation with Higgs portal

    SciTech Connect (OSTI)

    Baek, Seungwon; Ko, P.; Park, Wan-Il E-mail: pko@kias.re.kr

    2014-10-01

    We show that the 't Hooft-Polyakov monopole model in the hidden sector with Higgs portal interaction makes a viable dark matter model, where monopole and massive vector dark matter (VDM) are stable due to topological conservation and the unbroken subgroup U(1 {sub X}. We show that, even though observed CMB data requires the dark gauge coupling to be quite small, a right amount of VDM thermal relic can be obtained via s-channel resonant annihilation for the mass of VDM close to or smaller than the half of SM higgs mass, thanks to Higgs portal interaction. Monopole relic density turns out to be several orders of magnitude smaller than the observed dark matter relic density. Direct detection experiments, particularly, the projected XENON1T experiment, may probe the parameter space where the dark Higgs is lighter than ?< 50 GeV. In addition, the dark photon associated with the unbroken U(1 {sub X} contributes to the radiation energy density at present, giving ? N{sub eff}{sup ?} ? 0.1 as the extra relativistic neutrino species.

  4. TASI 2012 Lectures on Astrophysical Probes of Dark Matter

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    and rates? The second lecture discusses the thermal (or non-thermal) processes associated" miracle? What brackets the mass range for thermal relics? Where does v come from, and what does it mean with energy, and why does it not? How does one calculate the flux of neutrinos from dark matter annihilation

  5. 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.

  6. 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

  7. 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.

  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. 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

  10. 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.

  11. Modified holographic Ricci dark energy coupled to interacting relativistic and non-relativistic dark matter in the nonflat universe

    E-Print Network [OSTI]

    En-Kun Li; Yu Zhang; Jin-Ling Geng

    2014-12-16

    The modified holographic Ricci dark energy coupled to interacting relativistic and non-relativistic dark matter is considered in the nonflat Friedmann-Robertson-Walker universe. Through examining the deceleration parameter, one can find that the transition time of the Universe from decelerating to accelerating phase in the interacting holographic Ricci dark energy model is close to that in the $\\Lambda$ cold dark matter model. The evolution of modified holographic Ricci dark energy's state parameter and the evolution of dark matter and dark energy's densities shows that the dark energy holds the dominant position from the near past to the future. By studying the statefinder diagnostic and the evolution of the total pressure, one can find that this model could explain the Universe's transition from the radiation to accelerating expansion stage through the dust stage. According to the $Om$ diagnostic, it is easy to find that when the interaction is weak and the proportion of relativistic dark matter in total dark matter is small, this model is phantom-like. Through our studying, we find the interaction and the relativistic dark matter's proportion all have great influence on the evolution of the Universe.

  12. CONSTRAINTS ON DARK MATTER ANNIHILATION IN CLUSTERS OF GALAXIES FROM DIFFUSE RADIO EMISSION

    SciTech Connect (OSTI)

    Storm, Emma; Jeltema, Tesla E.; Profumo, Stefano [Department of Physics, University of California, 1156 High St., Santa Cruz, CA 95064 (United States); Rudnick, Lawrence [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

    2013-05-10

    Annihilation of dark matter can result in the production of stable Standard Model particles including electrons and positrons that, in the presence of magnetic fields, lose energy via synchrotron radiation, observable as radio emission. Galaxy clusters are excellent targets to search for or to constrain the rate of dark matter annihilation, as they are both massive and dark matter dominated. In this study, we place limits on dark matter annihilation in a sample of nearby clusters using upper limits on the diffuse radio emission, low levels of observed diffuse emission, or detections of radio mini-halos. We find that the strongest limits on the annihilation cross section are better than limits derived from the non-detection of clusters in the gamma-ray band by a factor of {approx}3 or more when the same annihilation channel and substructure model, but different best-case clusters, are compared. The limits on the cross section depend on the assumed amount of substructure, varying by as much as two orders of magnitude for increasingly optimistic substructure models as compared to a smooth Navarro-Frenk-White profile. In our most optimistic case, using the results of the Phoenix Project, we find that the derived limits reach below the thermal relic cross section of 3 Multiplication-Sign 10{sup -26} cm{sup 3} s{sup -1} for dark matter masses as large as 400 GeV, for the b b-bar annihilation channel. We discuss uncertainties due to the limited available data on the magnetic field structure of individual clusters. We also report the discovery of diffuse radio emission from the central 30-40 kpc regions of the groups M49 and NGC 4636.

  13. 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.

  14. Signatures of Horndeski gravity on the Dark Matter Bispectrum

    E-Print Network [OSTI]

    Emilio Bellini; Raul Jimenez; Licia Verde

    2015-05-12

    We present a detailed study of second-order matter perturbations for the general Horn- deski class of models. Being the most general scalar-tensor theory having second-order equations of motion, it includes many known gravity and dark energy theories and General Relativity with a cosmological constant as a specific case. This enables us to estimate the leading order dark matter bispectrum generated at late-times by gravitational instability. We parametrize the evolution of the first and second-order equations of motion as proposed by Bellini and Sawicki (2014), where the free functions of the theory are assumed to be proportional to the dark energy density. We show that it is unnatural to have large 10% ( 1%) deviations of the bispectrum introducing even larger ~ 30% (~ 5%) deviations in the linear growth rate. Considering that measurements of the linear growth rate have much higher signal-to-noise than bispectrum measurements, this indicates that for Horndeski models which reproduce the expansion history and the linear growth rate as predicted by GR the dark matter bispectrum kernel can be effectively modelled as the standard GR one. On the other hand, an observation of a large bispectrum deviation that can not be explained in terms of bias would imply either that the evolution of perturbations is strongly different than the evolution predicted by GR or that the theory of gravity is exotic (e.g., breaks the weak equivalence principle) and/or fine-tuned.

  15. Dark radiation and dark matter in supersymmetric axion models with high reheating temperature

    SciTech Connect (OSTI)

    Graf, Peter; Steffen, Frank Daniel, E-mail: graf@mpp.mpg.de, E-mail: steffen@mpp.mpg.de [Max-Planck-Institut für Physik, Föhringer Ring 6, D–80805 Munich (Germany)

    2013-12-01

    Recent studies of the cosmic microwave background, large scale structure, and big bang nucleosynthesis (BBN) show trends towards extra radiation. Within the framework of supersymmetric hadronic axion models, we explore two high-reheating-temperature scenarios that can explain consistently extra radiation and cold dark matter (CDM), with the latter residing either in gravitinos or in axions. In the gravitino CDM case, axions from decays of thermal saxions provide extra radiation already prior to BBN and decays of axinos with a cosmologically required TeV-scale mass can produce extra entropy. In the axion CDM case, cosmological constraints are respected with light eV-scale axinos and weak-scale gravitinos that decay into axions and axinos. These decays lead to late extra radiation which can coexist with the early contributions from saxion decays. Recent results of the Planck satellite probe extra radiation at late times and thereby both scenarios. Further tests are the searches for axions at ADMX and for supersymmetric particles at the LHC.

  16. Radio observations of the Galactic Centre and the Coma cluster as a probe of light dark matter self-annihilations and decay

    E-Print Network [OSTI]

    Celine Boehm; Joseph Silk; Torsten Ensslin

    2010-09-30

    We update our earlier calculations of gamma ray and radio observational constraints on annihilations of dark matter particles lighter than 10 GeV. We predict the synchrotron spectrum as well as the morphology of the radio emission associated with light decaying and annihilating dark matter candidates in both the Coma cluster and the Galactic Centre. Our new results basically confirm our previous findings: synchrotron emission in the very inner part of the Milky Way constrains or even excludes dark matter candidates if the magnetic field is larger than 50 micro Gauss. In fact, our results suggest that light annihilating candidates must have a S-wave suppressed pair annihilation cross section into electrons (or the branching ratio into electron positron must be small). If dark matter is decaying, it must have a life time that is larger than t = 3. 10^{25} s. Therefore, radio emission should always be considered when one proposes a "light" dark matter candidate.

  17. Modified Regge Calculus as an Explanation of Dark Matter

    E-Print Network [OSTI]

    Stuckey, W M; Silberstein, Michael

    2015-01-01

    According to modified Regge calculus (MORC), large-scale rarified distributions of matter can lead to perturbative corrections of the corresponding spacetime geometry of general relativity (GR). It is well known in GR that the dynamic mass of the matter generating the exterior Schwarzschild vacuum solution to Einstein's equations can differ from the proper mass of that same matter per the interior solution. For galactic rotation curves and the mass profiles of X-ray clusters, we use MORC to propose that it is precisely this type of mass difference on an enhanced scale that is currently attributed to non-baryonic dark matter. We argue that this same approach is applicable to Regge calculus cosmology and the modeling of anisotropies in the angular power spectrum of the CMB due to acoustic oscillations, so it should be applicable to explaining dark matter phenomena on that scale as well. We account for the value of the dynamic mass by a simple geometric scaling of the proper mass of the baryonic matter in galaxi...

  18. Direct Detection of Nonbaryonic Dark Matter

    E-Print Network [OSTI]

    Laura Baudis; H. V. Klapdor-Kleingrothaus

    2000-03-29

    Weakly Interacting Massive Particles (WIMPs) are leading candidates for the dominant part of the mass density of the Universe. Here we will review direct WIMP detection techniques by giving examples of currently running experiments, and present the status of the most promising future projects.

  19. Dark Matter Decay to a Photon and a Neutrino: the Double Monochromatic Smoking Gun Scenario

    E-Print Network [OSTI]

    Chaïmae El Aisati; Michael Gustafsson; Thomas Hambye; Tiziana Scarna

    2015-10-16

    In the energy range from few TeV to 25 TeV, upper bounds on the dark matter decay rate into high energy monochromatic neutrinos have recently become comparable to those on monochromatic gamma-ray lines. This implies clear possibilities of a future double "smoking-gun" evidence for the dark matter particle, from the observation of both a gamma and a neutrino line at the same energy. In particular, we show that a scenario where both lines are induced from the same dark matter particle decay leads to correlations that can already be tested. We study this "double monochromatic" scenario by considering the complete list of lowest dimensional effective operators that could induce such a decay. Furthermore, we argue that, on top of lines from decays into two-body final states, three-body final states can also be highly relevant. In addition to producing a distinct hard photon spectrum, three-body final states also produce a line-like feature in the neutrino spectrum that can be searched for by neutrino telescopes.

  20. Dark Matter Decay to a Photon and a Neutrino: the Double Monochromatic Smoking Gun Scenario

    E-Print Network [OSTI]

    Aisati, Chaïmae El; Hambye, Thomas; Scarna, Tiziana

    2015-01-01

    In the energy range from few TeV to 25 TeV, upper bounds on the dark matter decay rate into high energy monochromatic neutrinos have recently become comparable to those on monochromatic gamma-ray lines. This implies clear possibilities of a future double "smoking-gun" evidence for the dark matter particle, from the observation of both a gamma and a neutrino line at the same energy. In particular, we show that a scenario where both lines are induced from the same dark matter particle decay leads to correlations that can already be tested. We study this "double monochromatic" scenario by considering the complete list of lowest dimensional effective operators that could induce such a decay. Furthermore, we argue that, on top of lines from decays into two-body final states, three-body final states can also be highly relevant. In addition to producing a distinct hard photon spectrum, three-body final states also produce a line-like feature in the neutrino spectrum that can be searched for by neutrino telescopes.