Models of Neutrino Masses and Baryogenesis

TL;DR

This paper explores how different models of neutrino masses relate to the generation of the universe's baryon asymmetry, emphasizing the role of lepton number violation and electroweak sphalerons.

Contribution

It distinguishes between classes of neutrino mass models based on their compatibility with baryogenesis before the electroweak phase transition.

Findings

See-saw and triplet Higgs models are favored for baryogenesis.

Zee-type radiative and R-parity breaking models need additional mechanisms.

Models are discriminated based on their ability to generate baryon asymmetry.

Abstract

Majorana masses of the neutrino implies lepton number violation and is intimately related to the lepton asymmetry of the universe, which gets related to the baryon asymmetry of the universe in the presence of the sphalerons during the electroweak phase transition. Assuming that the baryon asymmetry of the universe is generated before the electroweak phase transition, it is possible to dicriminate different classes of models of neutrino masses. While see-saw mechanism and the triplet higgs mechanism are preferred, the Zee-type radiative models and the R-parity breaking models requires additional inputs to generate baryon asymmetry of the universe during the electroweak phase transition.