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Title: Particle Dark Matter constraints: the effect of Galactic uncertainties

Abstract

Collider, space, and Earth based experiments are now able to probe several extensions of the Standard Model of particle physics which provide viable dark matter candidates. Direct and indirect dark matter searches rely on inputs of astrophysical nature, such as the local dark matter density or the shape of the dark matter density profile in the target in object. The determination of these quantities is highly affected by astrophysical uncertainties. The latter, especially those for our own Galaxy, are ill-known, and often not fully accounted for when analyzing the phenomenology of particle physics models. In this paper we present a systematic, quantitative estimate of how astrophysical uncertainties on Galactic quantities (such as the local galactocentric distance, circular velocity, or the morphology of the stellar disk and bulge) propagate to the determination of the phenomenology of particle physics models, thus eventually affecting the determination of new physics parameters. We present results in the context of two specific extensions of the Standard Model (the Singlet Scalar and the Inert Doublet) that we adopt as case studies for their simplicity in illustrating the magnitude and impact of such uncertainties on the parameter space of the particle physics model itself. Our findings point towardmore » very relevant effects of current Galactic uncertainties on the determination of particle physics parameters, and urge a systematic estimate of such uncertainties in more complex scenarios, in order to achieve constraints on the determination of new physics that realistically include all known uncertainties.« less

Authors:
; ;  [1]; ;  [2]
  1. ICTP South American Institute for Fundamental Research Instituto de Física Teórica - Universidade Estadual Paulista (UNESP) Rua Dr. Bento Teobaldo Ferraz 271, 01140-070 São Paulo, SP Brazil (Brazil)
  2. GRAPPA Institute, Institute for Theoretical Physics Amsterdam and Delta Institute for Theoretical Physics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands)
Publication Date:
OSTI Identifier:
22680048
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 02; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; DENSITY; DISTANCE; GALAXIES; NONLUMINOUS MATTER; SPACE; STANDARD MODEL; UNCERTAINTY PRINCIPLE; VELOCITY

Citation Formats

Benito, Maria, Bernal, Nicolás, Iocco, Fabio, Bozorgnia, Nassim, and Calore, Francesca, E-mail: mariabenitocst@gmail.com, E-mail: nicolas.bernal@uan.edu.co, E-mail: n.bozorgnia@uva.nl, E-mail: calore@lapth.cnrs.fr, E-mail: fabio.iocco.astro@gmail.com. Particle Dark Matter constraints: the effect of Galactic uncertainties. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/02/007.
Benito, Maria, Bernal, Nicolás, Iocco, Fabio, Bozorgnia, Nassim, & Calore, Francesca, E-mail: mariabenitocst@gmail.com, E-mail: nicolas.bernal@uan.edu.co, E-mail: n.bozorgnia@uva.nl, E-mail: calore@lapth.cnrs.fr, E-mail: fabio.iocco.astro@gmail.com. Particle Dark Matter constraints: the effect of Galactic uncertainties. United States. doi:10.1088/1475-7516/2017/02/007.
Benito, Maria, Bernal, Nicolás, Iocco, Fabio, Bozorgnia, Nassim, and Calore, Francesca, E-mail: mariabenitocst@gmail.com, E-mail: nicolas.bernal@uan.edu.co, E-mail: n.bozorgnia@uva.nl, E-mail: calore@lapth.cnrs.fr, E-mail: fabio.iocco.astro@gmail.com. Wed . "Particle Dark Matter constraints: the effect of Galactic uncertainties". United States. doi:10.1088/1475-7516/2017/02/007.
@article{osti_22680048,
title = {Particle Dark Matter constraints: the effect of Galactic uncertainties},
author = {Benito, Maria and Bernal, Nicolás and Iocco, Fabio and Bozorgnia, Nassim and Calore, Francesca, E-mail: mariabenitocst@gmail.com, E-mail: nicolas.bernal@uan.edu.co, E-mail: n.bozorgnia@uva.nl, E-mail: calore@lapth.cnrs.fr, E-mail: fabio.iocco.astro@gmail.com},
abstractNote = {Collider, space, and Earth based experiments are now able to probe several extensions of the Standard Model of particle physics which provide viable dark matter candidates. Direct and indirect dark matter searches rely on inputs of astrophysical nature, such as the local dark matter density or the shape of the dark matter density profile in the target in object. The determination of these quantities is highly affected by astrophysical uncertainties. The latter, especially those for our own Galaxy, are ill-known, and often not fully accounted for when analyzing the phenomenology of particle physics models. In this paper we present a systematic, quantitative estimate of how astrophysical uncertainties on Galactic quantities (such as the local galactocentric distance, circular velocity, or the morphology of the stellar disk and bulge) propagate to the determination of the phenomenology of particle physics models, thus eventually affecting the determination of new physics parameters. We present results in the context of two specific extensions of the Standard Model (the Singlet Scalar and the Inert Doublet) that we adopt as case studies for their simplicity in illustrating the magnitude and impact of such uncertainties on the parameter space of the particle physics model itself. Our findings point toward very relevant effects of current Galactic uncertainties on the determination of particle physics parameters, and urge a systematic estimate of such uncertainties in more complex scenarios, in order to achieve constraints on the determination of new physics that realistically include all known uncertainties.},
doi = {10.1088/1475-7516/2017/02/007},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 02,
volume = 2017,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}
  • Indirect detection signals from dark matter annihilation are studied in the positron channel. We discuss in detail the positron propagation inside the galactic medium: we present novel solutions of the diffusion and propagation equations and we focus on the determination of the astrophysical uncertainties which affect the positron dark matter signal. We find dark matter scenarios and propagation models that nicely fit existing data on the positron fraction. Finally, we present predictions both on the positron fraction and on the flux for already running or planned space experiments, concluding that they have the potential to discriminate a possible signal frommore » the background and, in some cases, to distinguish among different astrophysical propagation models.« less
  • We present a new method for determining Weakly Interacting Massive Particle (WIMP) properties in future tonne scale direct detection experiments which accounts for uncertainties in the Milky Way (MW) smooth dark matter distribution. Using synthetic data on the kinematics of MW halo stars matching present samples from the Sloan Digital Sky Survey, complemented by local escape velocity constraints, we demonstrate that the local dark matter density can be constrained to ∼ 20% accuracy. For low mass WIMPs, we find that a factor of two error in the assumed local dark matter density leads to a severely biased reconstruction of themore » WIMP spin-independent cross section that is incorrect at the 15σ level. We show that this bias may be overcome by marginalizing over parameters that describe the MW potential, and use this formalism to project the accuracy attainable on WIMP properties in future 1 ton Xenon detectors. Our method can be readily applied to different detector technologies and extended to more detailed MW halo models.« less
  • For any realistic halo profile, the Galactic Center is predicted to be the brightest source of gamma-rays from dark matter annihilations. Due in large part to uncertainties associated with the dark matter distribution and astrophysical backgrounds, however, the most commonly applied constraints on the dark matter annihilation cross section have been derived from other regions, such as dwarf spheroidal galaxies. In this article, we study Fermi Gamma-Ray Space Telescope data from the direction of the inner Galaxy and derive stringent upper limits on the dark matter's annihilation cross section. Even for the very conservative case of a dark matter distributionmore » with a significant (~kpc) constant-density core, normalized to the minimum density needed to accommodate rotation curve and microlensing measurements, we find that the Galactic Center constraint is approximately as stringent as those derived from dwarf galaxies (which were derived under the assumption of an NFW distribution). For NFW or Einasto profiles (again, normalized to the minimum allowed density), the Galactic Center constraints are typically stronger than those from dwarfs.« less
  • The existence of dark matter (DM) at scales of a few parsecs down to {approx_equal}10{sup -5} pc around the centers of galaxies and, in particular, in the Galactic Center region has been considered in the literature. Under the assumption that such a DM clump, principally constituted by nonbaryonic matter (like weakly interacting massive particles) does exist at the center of our galaxy, the study of the {gamma}-ray emission from the Galactic Center region allows us to constrain both the mass and the size of this DM sphere. Further constraints on the DM distribution parameters may be derived by observations ofmore » bright infrared stars around the Galactic Center. Hall and Gondolo [J. Hall and P. Gondolo, Phys. Rev. D 74, 063511 (2006)] used estimates of the enclosed mass obtained in various ways and tabulated by Ghez et al. [A. M. Ghez et al., Astron. Nachr. 324, 527 (2003); A. M. Ghez et al., Astrophys. J. 620, 744 (2005)]. Moreover, if a DM cusp does exist around the Galactic Center it could modify the trajectories of stars moving around it in a sensible way depending on the DM mass distribution. Here, we discuss the constraints that can be obtained with the orbit analysis of stars (as S2 and S16) moving inside the DM concentration with the present and next generations of large telescopes. In particular, consideration of the S2 star apoastron shift may allow improving limits on the DM mass and size.« less
  • Annihilation of dark matter usually produces together with gamma rays comparable amounts of electrons and positrons. The e{sup +}e{sup -} gyrating in the galactic magnetic field then produce secondary synchrotron radiation which thus provides an indirect means to constrain the DM signal itself. To this purpose, we calculate the radio emission from the galactic halo as well as from its expected substructures and we then compare it with the measured diffuse radio background. We employ a multifrequency approach using data in the relevant frequency range 100 MHz-100 GHz, as well as the WMAP haze data at 23 GHz. The derivedmore » constraints are of the order <{sigma}{sub A}v>=10{sup -24} cm{sup 3} s{sup -1} for a DM mass m{sub {chi}}=100 GeV sensibly depending, however, on the astrophysical uncertainties, in particular, on the assumption of the galactic magnetic field model. The signal from single bright clumps is instead largely attenuated by diffusion effects and offers only poor detection perspectives.« less