Lepton number symmetry as a way to testable leptogenesis

TL;DR

This paper introduces a minimal extension of the Standard Model with approximate lepton number conservation, capable of explaining neutrino masses and baryogenesis via leptogenesis with GeV-scale sterile fermions, and explores its testability.

Contribution

It presents a new model linking neutrino masses and baryogenesis through a minimal lepton number conserving extension, analyzing its parameter space and experimental prospects.

Findings

Viable parameter space identified for neutrino and baryogenesis phenomenology.

Different leptogenesis regimes analyzed for early Universe asymmetry generation.

Model's testability in future experiments evaluated.

Abstract

We propose a minimal and motivated extension of the Standard Model characterised by an approximate lepton number conservation, which is able to simultaneously generate neutrino masses and to account for a successful baryogenesis via leptogenesis. The sterile fermions involved in the leptogenesis process have masses at the GeV scale. We determine the viable parameter space that complies with both the neutrino and baryogenesis phenomenology, and analyse the different regimes for the generation of a lepton asymmetry in the early Universe (weak and strong-washout) in order to determine their testability in future experimental facilities.