Leptogenesis in GeV scale seesaw models

TL;DR

This paper investigates how leptonic asymmetries can be generated in minimal Standard Model extensions with GeV-scale Majorana neutrinos, using analytical and numerical methods to explore parameter space.

Contribution

It provides an analytical approach to identify CP invariants and explores the parameter space for viable leptogenesis in GeV-scale seesaw models.

Findings

Sizeable lepton asymmetries are compatible with non-degenerate neutrino masses.

Active-sterile mixings can be measurable.

Analytical solutions simplify the exploration of parameter space.

Abstract

We revisit the production of leptonic asymmetries in minimal extensions of the Standard Model that can explain neutrino masses, involving extra singlets with Majorana masses in the GeV scale. We study the quantum kinetic equations both analytically, via a perturbative expansion up to third order in the mixing angles, and numerically. The analytical solution allows us to identify the relevant CP invariants, and simplifies the exploration of the parameter space. We find that sizeable lepton asymmetries are compatible with non-degenerate neutrino masses and measurable active-sterile mixings.