A new leptogenesis scenario parametrized by Dirac neutrino mass matrix

TL;DR

This paper proposes a novel leptogenesis mechanism within a left-right symmetric model, linking Dirac neutrino masses to baryon asymmetry generation via mirror neutrino decays and parity symmetry.

Contribution

It introduces a new leptogenesis scenario parametrized by the Dirac neutrino mass matrix in a left-right symmetric framework with mirror fields.

Findings

Mirror neutrinos decay to generate lepton asymmetry.

Mirror muon asymmetry partially converts to baryon asymmetry.

The model connects neutrino masses to baryogenesis.

Abstract

In an $SU(3)_{c}\times SU(2)_{L}\times SU(2)_{R}\times U(1)_{B-L}$ left-right symmetric framework, we present a new leptogenesis scenario parametrized by Dirac neutrino mass matrix. Benefited from the parity symmetry motivated to solve the strong CP problem, the dimensionless couplings of the mirror fields are identified to those of the ordinary fields. In particular, the mirror Dirac neutrinos have a heavy mass matrix proportional to the light mass matrix of the ordinary Dirac neutrinos. Through the $SU(2)_R$ gauge interactions, the mirror neutrinos can decay to generate a lepton asymmetry in the mirror muons and an opposite lepton asymmetry in the mirror electrons. Before the $SU(2)_L$ sphaleron processes stop working, the mirror muons can efficiently decay into the ordinary right-handed leptons with a dark matter scalar and hence the mirror muon asymmetry can be partially converted to a desired baryon asymmetry.