B-L Conserved Baryogenesis

TL;DR

This paper explores a baryogenesis scenario within an SU(5) GUT framework where B-L symmetry is conserved, allowing for matter-antimatter asymmetry generation without B-L violation, and naturally explains small Dirac neutrino masses.

Contribution

It proposes a novel SU(5) GUT model that conserves B-L and accounts for small Dirac neutrino masses, offering an alternative baryogenesis mechanism.

Findings

B-L conserved baryogenesis is feasible within SU(5) GUT.

The model naturally explains small Dirac neutrino masses.

Baryon asymmetry can be generated without B-L violation.

Abstract

In the presence of anomaly induced sphaleron process, only a B-L asymmetry can be partially converted to the baryon asymmetry while any B+L asymmetry would be completely erased. Thus in any successful baryogenesis theories, B-L is usually violated above the electroweak scale to explain the observed matter-antimatter asymmetry of the universe. However, if any lepton asymmetry is not affected by the sphaleron processes, a B-L conserved theory can still realize the baryogenesis. We present here an SU(5) GUT realization of this scenario, which naturally accommodates small masses of Dirac neutrinos.