http://arxiv.org/abs/1710.01853
A generic 2-3 component dark matter setup has been discussed. Dark matter candidates have been stabilized by a discrete $Z_2 !\times! Z_2^\prime$ symmetry. It turns out that non-trivial and interesting implications of multi-component dark sector emerge if standard annihilation channels are suppressed. In that case semi-annihilations, conversions and decays are crucial for the evolution of the dark matter abundance and its present value. The generic observations have been illustrated within a simple extension of the Standard Model (SM) by an extra $U(1)X$ gauge symmetry and an extra Dirac fermion. To generate the mass for the dark-vector $X\mu$ we have employed the Higgs mechanism in the dark sector with a complex singlet $S$. Dark matter candidates are a massive vector boson $X_\mu$ and two Majorana fermions $\psi_\pm$. All the dark sector fields are singlets under the SM gauge group. The set of three Boltzmann equations has been solved numerically and discussed. The dynamics of the system is very rich and various new phenomena may appear, for instance, it has been shown that even if only one dark component dominates the present abundance, its value can crucially depend on interactions within the dark sector.
A. Ahmed, M. Duch, B. Grzadkowski, et. al.
Fri, 6 Oct 17
20/51
Comments: 31 pages and 13 figures
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