Flavoured CP asymmetries for type II seesaw leptogenesis

TL;DR

This paper introduces a new CP asymmetry contribution in type II seesaw leptogenesis that arises from flavor effects, which could significantly impact baryon asymmetry generation.

Contribution

It presents a novel CP asymmetry mechanism in flavoured leptogenesis scenarios, highlighting its potential dominance in baryon asymmetry production.

Findings

New CP asymmetry contribution identified

Flavor effects can lead to dominant asymmetry mechanisms

Implications for baryon asymmetry generation

Abstract

A novel contribution to the leptonic CP asymmetries in type II seesaw leptogenesis scenarios is obtained for the cases in which flavor effects are relevant for the dynamics of leptogenesis. In the so-called flavoured leptogenesis regime, the interference between the tree-level amplitude of the scalar triplet decaying into two leptons and the one-loop wave-function correction with leptons in the loop, leads to a new nonvanishing CP asymmetry contribution. The latter conserves total lepton number but violates lepton flavour. Cases in which this novel contribution may be dominant in the generation of the baryon asymmetry are briefly discussed.