Interplay between dark matter and leptogenesis in a common framework

TL;DR

This paper explores a unified framework where dark matter and leptogenesis are interconnected through singlet scalars and right-handed neutrinos, revealing how dark matter influences baryon asymmetry and identifying viable parameter spaces.

Contribution

It introduces a model linking dark matter relic density with leptogenesis via scalar mixing, demonstrating enhanced baryon asymmetry effects and flexible parameter space at TeV scales.

Findings

Dark matter can dilute or enhance baryon asymmetry.

Dark matter annihilation into right-handed neutrinos affects asymmetry.

Viable parameter space exists with TeV-scale right-handed neutrinos.

Abstract

We consider the interplay between dark matter and leptogenesis in a common framework, where three right-handed neutrinos, one fermionic dark matter and two singlet scalars are introduced into the Standard Model. The mixing of the two singlet scalars not only determine the dark matter relic density but also connect right-handed neutrino with dark matter. We consider that the baryon asymmetry is generated via the resonant leptogenesis and the right-handed neutrino masses are at TeV level. We present a viable parameter space satisfying relic density constraint, and the parameter space is more flexible in the case of a larger mixing angle. We found that the existence of dark matter in the model can not only dilute the baryon asymmetry but can also generate a larger baryon asymmetry due to the process of dark matter annihilation into a pair of right-handed neutrinos even though dark matter mass is lighter than right-handed neutrino mass. The enhanced effect depends on the dark matter mass $m_{\chi}$ as well as right-handed neutrino mass $m_N$, and one still can find a baryon asymmetry enhanced in the case of $m_N=800$ GeV.