MeV scale model of SIMP dark matter, neutrino mass and leptogenesis

Abstract

We consider a simple extension of the Standard Model with two singlet scalar fields and three heavy right-handed neutrinos. One of the scalar fields serves as an MeV scale dark matter and its stability is ensured by the introduction of an extra Z2 symmetry. The second scalar (which is even under the Z2 symmetry) generates the mass term of the scalar, contributes to the 3 arrow 2 annihilation process required for the correct relic density of the dark matter and it also contributes to the leptogenesis. The right-handed neutrinos are responsible for the generation of light neutrino masses through Type-I seesaw mechanism. The decay of the heavy right-handed neutrino can generate the lepton asymmetry which can then be converted to baryon asymmetry through sphaleron transitions.