From high-scale leptogenesis to low-scale one-loop neutrino mass generation

TL;DR

This paper demonstrates that high-scale leptogenesis can be compatible with low-scale one-loop neutrino mass generation within a specific gauge symmetry framework, introducing new particles and mechanisms for asymmetry and mass generation.

Contribution

It presents a novel model combining high-scale leptogenesis with low-scale radiative neutrino mass generation using an extended gauge symmetry and discrete Z_2 symmetry.

Findings

High-scale leptogenesis can produce the observed matter-antimatter asymmetry.

Neutrino masses are generated radiatively at the TeV scale.

The lightest right-handed neutrino can be a dark matter candidate.

Abstract

We show that a high-scale leptogenesis can be consistent with a low-scale one-loop neutrino mass generation. Our models are based on the SU(3)_c\times SU(2)_L\times U(1)_Y\times U(1)_{B-L} gauge groups. Except a complex singlet scalar for the U(1)_{B-L} symmetry breaking, the other new scalars and fermions (one scalar doublet, two or more real scalar singlets/triplets and three right-handed neutrinos) are odd under an unbroken Z_2 discrete symmetry. The real scalar decays can produce an asymmetry stored in the new scalar doublet which subsequently decays into the standard model lepton doublets and the right-handed neutrinos. The lepton asymmetry in the standard model leptons then can be partially converted to a baryon asymmetry by the sphaleron processes. By integrating out the heavy scalar singlets/triplets, we can realize an effective theory to radiatively generate the small neutrino masses at the TeV scale. Furthermore, the lightest right-handed neutrino can serve as a dark matter candidate.