Leptogenesis from a feebly interacting dark matter sector

We perform an analysis of leptogenesis in the context of a simple extension of the Standard Model with two fermions, one charged (x) and one neutral (yr), in addition to three right-handed neutrinos, interacting through a charged gauge singlet scalar S. The dark sector (x and yr) interacts feebly and produces a relic density consistent with the existing data. The right-handed neutrinos decay into the charged scalar S and a lepton, providing, along with the virtual exchange of S in the standard decay channel, an additional source of CP asymmetry. The advantage of this scenario is that it can generate naturally the observed baryon asymmetry of the Universe, even for right-handed neutrino masses in 10 TeV region, without requiring neutrinos to be degenerate.

Automated summary

In this study, leptogenesis is analyzed in the context of a simple extension of the Standard Model. By introducing two fermions and interacting with three right-handed neutrinos through a charged gauge singlet scalar S, the observed baryon asymmetry of the Universe can be naturally generated.