The role of lepton flavor symmetries in leptogenesis

TL;DR

This paper reviews how lepton flavor symmetries influence leptogenesis across various seesaw models, examining scenarios with and without flavor symmetry breaking and their impact on generating the Universe's baryon asymmetry.

Contribution

It provides a comprehensive review of the role of flavor symmetries in leptogenesis within type-I, II, and III seesaw models, including extended models and their viability.

Findings

Flavor symmetries affect leptogenesis mechanisms.

Extended seesaw models can still produce viable leptogenesis.

Exact mixing patterns do not necessarily prevent successful leptogenesis.

Abstract

The presence of flavor symmetries in the lepton sector may have several consequences for the generation of the baryon asymmetry of the Universe via leptogenesis. We review the mechanism in general type-I, type-II and type-III seesaw models. We then turn to the discussion of the cases when the asymmetry is generated in the context of seesaw models extended with flavor symmetries, before or after flavor symmetry breaking. Finally we explain how the interplay between type-I and type-II seesaws can (or not) lead to viable models for leptogenesis even when there is an exact mixing pattern enforced by the flavor symmetry.