Cosmology and Astrophysics of Minimal Dark Matter

Abstract

We consider DM that only couples to SM gauge bosons and fills one gauge multiplet, e.g. a fermion 5-plet (which is automatically stable), or a wino-like 3-plet. We revisit the computation of the cosmological relic abundance including non-perturbative corrections. The predicted mass of e.g. the 5-plet increases from 4.4 TeV to 10 TeV, and indirect detection rates are enhanced by 2 orders of magnitude. Next, we show that due to the quasi-degeneracy among neutral and charged components of the DM multiplet, a significant fraction of DM with energy E > 10^17 eV (possibly present among ultra-high energy cosmic rays) can cross the Earth exiting in the charged state and may in principle be detected in neutrino telescopes.Comment: 24 pages, 10 figures; v2: typos corrected, to appear on NP