Non-thermal dark matter production and leptogenesis in a $L_{\mu}-L_{\tau}$ model

TL;DR

This paper explores a non-thermal mechanism for light scalar dark matter production via right-handed neutrinos in an $L_{}-L_{}$ model, ensuring compatibility with leptogenesis and identifying viable dark matter mass ranges.

Contribution

It introduces a non-thermal dark matter production scenario in an $L_{}-L_{}$ model that preserves leptogenesis outcomes and delineates the parameter space for viable dark matter masses.

Findings

Correct relic density achieved without affecting leptogenesis.

Dark matter mass range identified as $[10^{-5} ext{ GeV}, 0.1 ext{ GeV}]$.

Heavier right-handed neutrinos lead to colder dark matter production.

Abstract

We discuss the possibility of light scalar dark matter generated by right-handed neutrino in a $L_{\mu}-L_{\tau}$ model, in which the dark matter $\phi_{dm}$ carries $U(1)_{L_{\mu}-L_{\tau}}$ charge but it is a singlet in the Standard Model. We discuss the case that dark matter production mainly comes from scattering associated with a pair of right-handed neutrinos non-thermally while other related processes are highly suppressed. A feasible parameter space is considered and we found the correct dark matter relic density can be obtained without influencing the result of leptogenesis result. The heavier right-handed neutrino will induce colder dark matter production and the allowed dark matter mass region is $[\rm 10^{-5}\ GeV,0.1\ GeV]$.