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

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 ${\varphi }_{dm}$ 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 $[10^{-5}\mathrm{GeV},0.1\mathrm{GeV}]$.