http://arxiv.org/abs/1407.7874
We show that the relic abundance of thermal dark matter annihilating via a long-range interaction, is significantly affected by the formation and decay of dark matter bound states in the early universe, if the dark matter mass is above a few TeV. We determine the coupling required to obtain the observed dark matter density, taking into account both the direct 2-to-2 annihilations and the formation of bound states. We argue that the unitarity limit on the inelastic cross-section is realized only if dark matter annihilates via a long-range interaction, and we determine the upper bound on the mass of thermal-relic dark matter to be about 139 TeV for dark matter consisting of Dirac fermions.
B. Harling and K. Petraki
Thu, 7 Aug 14
11/46
Comments: 7 pages, 2 figures, 1 table