Protohalo constraints to the resonant annihilation of dark matter

Journal Article · Thu Oct 15 04:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.80.081302· OSTI ID:21325297

Cyr-Racine, Francis-Yan; Sigurdson, Kris ^[1]; Profumo, Stefano ^[2]

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1. Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada)
2. Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz California 95064 (United States)

It has recently been argued that the PAMELA, ATIC, and PPB-BETS data showing an anomalous excess of high-energy cosmic ray positrons and electrons might be explained by dark matter annihilating in the Galactic halo with a cross section resonantly enhanced compared to its value in the primeval plasma. We find that with a very large annihilation cross section the flash of energetic photons and electron-positron pairs expected from dark-matter annihilation in the first protohalos that form at redshift z{approx}40 is likely substantial and observable. As a consequence, bounds on the allowed energy injection into the primordial gas and the energy density of the diffuse gamma-ray background give rise to limits on the low-velocity dark-matter cross section that can be difficult to reconcile with this interpretation of the PAMELA, ATIC, and PPB-BETS results.

• OSTI ID: 21325297
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 8 Vol. 80; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
COSMIC ELECTRONS
COSMIC POSITRONS
COSMIC RADIATION
CROSS SECTIONS
ELECTRON-POSITRON INTERACTIONS
ENERGY DENSITY
GAMMA RADIATION
NONLUMINOUS MATTER
PHOTONS
RED SHIFT
VELOCITY