Baryogenesis through leptogenesis

TL;DR

This paper reexamines baryogenesis via leptogenesis, focusing on flavor effects and providing analytic solutions, comparing models with Abelian and non-Abelian family symmetries to show consistent baryogenesis mechanisms.

Contribution

It introduces an approximate analytic solution to the evolution equations of leptogenesis, considering flavor effects and comparing different neutrino mass models.

Findings

Consistent baryogenesis can occur in both U(1) and U(2) symmetry models.

Flavor structure significantly impacts baryogenesis outcomes.

Analytic solutions effectively describe the evolution of baryon asymmetry.

Abstract

Baryogenesis by heavy-neutrino decay and sphaleron reprocessing of both baryon and lepton number is reconsidered, paying special attention to the flavour structure of the general evolution equations and developing an approximate but sufficiently accurate analytic solution to the prototype evolution equation. Two different models of neutrino masses are examined, based on an Abelian U(1) or a non-Abelian U(2) family symmetry. We show that a consistent picture of baryogenesis can emerge in both cases, although with significant differences.