Light dark matter from dark sector decay

TL;DR

This paper explores a model where light dark matter is produced through decay in a dark sector involving right-handed neutrinos and scalar/fermion singlets, achieving the correct relic density with very weak interactions.

Contribution

It introduces a novel decay-based production mechanism for light dark matter within a specific dark sector model involving right-handed neutrinos and singlet particles.

Findings

Dark matter can have GeV or MeV scale mass.

The dark sector scalar interacts weakly with the Standard Model.

The dark matter relic density can be achieved through decay processes.

Abstract

We study the possibility that light dark matter can be produced with right relic density by the decay of other dark sector particles. We study this possibility in a model with right-handed neutrinos, a dark sector singlet scalar and a dark sector singlet fermion. The decay of the heavier dark sector singlet scalar gives rise to the lighter dark sector singlet fermion which serves as the dark matter candidate. We show that the right dark matter relic density can be produced by the decay of the dark sector singlet scalar. We find that the mass of the dark sector singlet fermion can be GeV scale or MeV scale and the interaction of the dark sector singlet fermion is very weak. The dark sector singlet scalar can have a mass of GeV-TeV scale and can have weak scale interactions with the Standard Model(SM) particles. So, in this scenario, dark matter has an interaction with the SM much weaker than the weak interaction, but the dark sector still has weak scale interaction with the SM.