Squeezing out predictions with leptogenesis from SO(10)

TL;DR

This paper presents a predictive SO(10) model linking neutrino properties and leptogenesis, successfully explaining the observed baryon asymmetry with minimal assumptions.

Contribution

It introduces a non-supersymmetric SO(10) framework that tightly constrains neutrino parameters and predicts the right-handed neutrino spectrum and leptogenesis outcomes.

Findings

Neutrino mass scale and phases are determined by low-energy data.

Right-handed neutrino spectrum is predicted within the model.

Leptogenesis produces the correct baryon asymmetry.

Abstract

We consider the see-saw mechanism within a non-supersymmetric SO(10) model. By assuming the SO(10) quark-lepton symmetry, and after imposing suitable conditions that ensure that the right-handed (RH) neutrino masses are at most mildly hierarchical (compact RH spectrum) we obtain a surprisingly predictive scenario. The absolute neutrino mass scale, the Dirac and the two Majorana phases of the neutrino mixing matrix remain determined in terms of the set of already measured low energy observables, modulo a discrete ambiguity in the signs of two neutrino mixing angles and of the Dirac phase. The RH neutrinos mass spectrum is also predicted, as well as the size and sign of the leptogenesis CP asymmetries. We compute the cosmological baryon asymmetry generated through leptogenesis and obtain the correct sign and a size compatible with observations.