Baryogenesis via Leptogenesis in Adjoint SU(5)

TL;DR

This paper explores how leptogenesis within the Adjoint SU(5) model can explain the Universe's baryon asymmetry, identifying specific mass ranges for the rho_3 field that produce successful baryogenesis.

Contribution

It demonstrates that leptogenesis in Adjoint SU(5) can account for baryon asymmetry, constraining the model's parameter space based on neutrino hierarchy and CP asymmetry sources.

Findings

Successful leptogenesis occurs for specific rho_3 mass ranges.

CP asymmetry arises only from vertex correction, not self-energy.

Constraints exclude large parts of the parameter space.

Abstract

The possibility to explain the baryon asymmetry in the Universe through the leptogenesis mechanism in the context of Adjoint SU(5) is investigated. In this model the neutrino masses are generated through the Type I and Type III seesaw mechanisms, and the field responsible for the Type III seesaw, called rho_3, generates the B-L asymmetry needed to satisfy the observed value of the baryon asymmetry in the Universe. We find that the CP asymmetry originates only from the vertex correction, since the self-energy contribution is not present. When neutrino masses have a normal hierarchy, successful leptogenesis is possible for 10^{11} GeV < M_{\rho_3}^{NH} < 4 10^{14} GeV. When the neutrino hierarchy is inverted, the allowed mass range changes to 2 10^{11} GeV < M_{\rho_3}^{IH} < 5 10^{11} GeV. These constraints make possible to rule out a large part of the parameter space in the theory which was allowed by the unification of gauge interactions and the constraints coming from proton decay.