paper

Ultra-high energy cosmic rays from annihilation of superheavy dark matter

arXiv:astro-ph/0105232 · doi:10.1016/S0927-6505(02)00113-5

Abstract

We consider the possibility that ultra-high energy cosmic rays originate from the annihilation of relic superheavy dark-matter particles. We find that a cross section of <sigma_A v> ~ 10^{-26}cm^2 (M_X/10^{12}GeV)^{3/2} is required to account for the observed rate of super-GZK events if the superheavy dark matter follows a Navarro-Frenk-White density profile. This would require extremely large-l contributions to the annihilation cross section. We also calculate the possible signature from annihilation in sub-galactic clumps of dark matter and find that the signal from sub-clumps dominates and may explain the observed flux with a much smaller cross section than if the superheavy dark matter is smoothly distributed. Finally, we discuss the expected anisotropy in the arrival directions of the cosmic rays, which is a characteristic signature of this scenario.

13 pages, 4 figures, to appear in Astropart. Phys

References in corpus (2)

Cited by in corpus (47)