Resonant SIMP dark matter

Abstract

We consider a resonant SIMP dark matter in models with two singlet complex scalar fields charged under a local dark U(1)(D). After the U(1)(D) is broken down to a Z(5) discrete subgroup, the lighter scalar field becomes a SIMP dark matter which has the enhanced 3 -> 2 annihilation cross section near the resonance of the heavier scalar field. Bounds on the SIMP self-scattering cross section and the relic density can be fulfilled at the same time for perturbative couplings of SIMP. A small gauge kinetic mixing between the SM hypercharge and dark gauge bosons can be used to make SIMP dark matter in kinetic equilibrium with the SM during freeze-out. (C) 2016 The Authors. Published by Elsevier B.V.