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

Journal Article · Wed Apr 15 00:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.79.081303· OSTI ID:21308239

Bergstroem, Lars; Bringmann, Torsten; Edsjoe, Joakim ^[1]; Bertone, Gianfranco ^[2]; Taoso, Marco ^[2]

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1. Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, AlbaNova, SE--106 91 Stockholm (Sweden)
2. Institut d'Astrophysique de Paris, UMR7095-CNRS Universite Pierre et Marie Curie, 98bis Boulevard Arago, 75014 Paris (France)

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.

• OSTI ID: 21308239
• Journal Information: Physical Review. D, Particles Fields, Vol. 79, Issue 8; Other Information: DOI: 10.1103/PhysRevD.79.081303; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
ANTIPROTONS
BRANCHING RATIO
COMPARATIVE EVALUATIONS
COSMIC PHOTONS
CROSS SECTIONS
DENSITY
ELECTRON-POSITRON INTERACTIONS
ELECTRONS
GALAXIES
GAMMA RADIATION
MASS
MUONS MINUS
MUONS PLUS
NONLUMINOUS MATTER
PARTICLE DECAY
PHOTONS
POSITRONS
QUANTUM ELECTRODYNAMICS
RADIATIVE CORRECTIONS
SIMULATION
SYNCHROTRON RADIATION