Bridging flavour violation and leptogenesis in SU(3) family models

TL;DR

This paper explores minimal Pati-Salam x SU(3) family models with Type I see-saw to simultaneously explain neutrino properties, baryon asymmetry, and lepton flavour violation, highlighting the role of different SU(3) messengers.

Contribution

It introduces a new fit of Yukawa textures in SU(3) family models and demonstrates how various SU(3) messengers influence flavour violation and baryogenesis compatibility.

Findings

Different SU(3) messengers lead to varied Yukawa couplings.

Models can now simultaneously explain neutrino data, baryon asymmetry, and lepton flavour violation.

A new Yukawa texture fit improves model consistency.

Abstract

We reconsider basic, in the sense of minimal field content, Pati-Salam x SU(3) family models which make use of the Type I see-saw mechanism to reproduce the observed mixing and mass spectrum in the neutrino sector. The goal of this is to achieve the observed baryon asymmetry through the thermal decay of the lightest right-handed neutrino and at the same time to be consistent with the expected experimental lepton flavour violation sensitivity. This kind of models have been previously considered but it was not possible to achieve a compatibility among all of the ingredients mentioned above. We describe then how different SU(3) messengers, the heavy fields that decouple and produce the right form of the Yukawa couplings together with the scalars breaking the SU(3) symmetry, can lead to different Yukawa couplings. This in turn implies different consequences for flavour violation couplings and conditions for realizing the right amount of baryon asymmetry through the decay of the lightest right-handed neutrino. Also a highlight of the present work is a new fit of the Yukawa textures traditionally embedded in SU(3) family models.