Leptogenesis in SO(10)

TL;DR

This paper demonstrates that in SO(10) GUTs, the baryon asymmetry via leptogenesis can be predicted from low energy data and a single high energy parameter, with new decay channels influencing the outcome.

Contribution

It establishes a method to connect low energy observables with leptogenesis in SO(10) models, including new decay channels for heavy neutrinos, and shows successful baryon asymmetry predictions.

Findings

Baryon asymmetry is determined by low energy data and one high energy parameter.

New decay channels for Majorana neutrinos significantly impact baryon asymmetry.

Successful leptogenesis consistent with observations is achievable in SO(10) models.

Abstract

We consider $SO(10)$ Grand Unified Theories (GUTs) with vacuum expectation values (vevs) for fermion masses in the $\mathbf{10} + \mathbf{\overline{126}}$ representation. We show that the baryon asymmetry generated via leptogenesis is completely determined in terms of measured low energy observables and of one single high energy parameter related to the ratio of the $\mathbf{10}$ and $\mathbf{\overline{126}}$ $SU(2)$ doublet vevs. We identify new decay channels for the heavy Majorana neutrinos into $SU(2)$ singlet leptons $e^c$ which can sizeably affect the size of the resulting baryon asymmetry. We describe how to equip $SO(10)$ fits to low energy data with the additional constraint of successful leptogenesis, and we apply this procedure to the fits carried out in ref.~\cite{Dueck:2013gca}. We show that a baryon asymmetry in perfect agreement with observations is obtained.