New Solution for Neutrino Masses and Leptogenesis in Adjoint SU(5)

TL;DR

This paper proposes a new model within Adjoint SU(5) that combines multiple seesaw mechanisms and one-loop processes to explain neutrino masses and baryogenesis via leptogenesis, expanding the viable parameter space.

Contribution

It introduces a novel approach integrating Type I, Type III seesaw, and one-loop mechanisms in Adjoint SU(5) for neutrino mass and leptogenesis, allowing for an inverted hierarchy.

Findings

One light neutrino remains massless.

Heavy Majorana fermions contribute non-linearly to neutrino masses.

New parameter space for successful leptogenesis, including inverted hierarchy.

Abstract

We investigate baryogenesis via leptogenesis and generation of neutrino masses and mixings through the Type I plus Type III seesaw plus an one-loop mechanism in the context of Renormalizable Adjoint SU(5) theory. One light neutrino remains massless, because the contributions of three heavy Majorana fermions \rho_0, \rho_3 and \rho_8 to the neutrino mass matrix are not linearly independent. However none of these heavy fermions is decoupled from the generation of neutrino masses. This opens a new range in parameter space for successful leptogenesis, in particular, allows for inverted hierarchy of the neutrino masses.