Leptogenesis constraints from flavour symmetry induced lepton mixing

TL;DR

This paper explores how flavour symmetries in Standard Model extensions influence leptogenesis, showing that certain symmetries lead to zero CP asymmetry in unflavoured leptogenesis within type I see-saw models.

Contribution

It provides a model-independent analysis demonstrating that exact mass-independent lepton mixing schemes result in vanishing CP asymmetry for unflavoured leptogenesis.

Findings

Exact mass-independent lepton mixing schemes lead to zero CP asymmetry.

The analysis applies generally to unflavoured leptogenesis in type I see-saw models.

Flavour symmetries can constrain leptogenesis mechanisms.

Abstract

In models with flavour symmetries added to the gauge group of the Standard Model the CP-violating asymmetry necessary for leptogenesis may be related with low-energy parameters. A particular case of interest is when the flavour symmetry produces an exact mass independent lepton mixing scheme, leading to a vanishing CP-violating asymmetry. We present a model-independent discussion that confirms this always occurs for unflavoured leptogenesis in type I see-saw scenarios.