Neutrino Mixings in SO(10) with Type II Seesaw and theta_{13}

TL;DR

This paper explores a supersymmetric SO(10) grand unified theory with type II seesaw, predicting neutrino mixing angles and CP phases, and providing testable correlations among mixing parameters.

Contribution

It introduces a model with broken S_4 symmetry leading to specific neutrino mixing predictions, including a small theta_{13} and CP phase, fitting fermion masses and mixings.

Findings

Predicted theta_{13} ~ 4-6 degrees.

Dirac CP phase between -10 and +15 degrees.

Correlations between mixing angles for experimental testing.

Abstract

We analyze a class of supersymmetric SO(10) grand unified theories with type II seesaw for neutrino masses, where the contribution to PMNS matrix from the neutrino sector has an exact tri-bi-maximal (TBM) form, dictated by a broken S_4 symmetry. The Higgs fields that determine the fermion masses are two 10 fields and one 126 field, with the latter simultaneously contributing to neutrino as well as charged fermion masses. Fitting charged fermion masses and the CKM mixings lead to corrections to the TBM mixing that determine the final PMNS matrix with the predictions theta_{13} ~ 4-6 degrees and the Dirac CP phase to be between -10 and +15 degrees. We also show correlations between various mixing angles which can be used to test the model.