\theta_{13} and Proton Decay in a Minimal SO(10) x S_4 model of Flavor

TL;DR

This paper presents a minimal SUSY SO(10) x S_4 model that successfully predicts fermion masses, mixings, and neutrino parameters, including a large heta_{13}, and forecasts proton decay within experimental reach.

Contribution

It introduces a minimal, parameter-reduced flavor model with dynamic Yukawa couplings, extending to explain recent neutrino mixing data and proton decay predictions.

Findings

Predicts heta_{13} \\sim 9 degrees consistent with experiments.

Proton decay mode p -> K^+ \\sim 10^{34} years, accessible in future searches.

Higgs mass constraints imply lower bounds on light stop masses.

Abstract

In a recent paper, a minimal supersymmetric (SUSY) SO(10)xS_4 based unified model of flavor for quarks and leptons was proposed with two 10 and one 126 contributing to fermion masses. An important aspect of this model is that Yukawa couplings emerge dynamically from minimization of the flavon potential, thereby reducing the number of parameters considerably. We make a detailed numerical analysis of this model for fermion mixings including SUSY threshold effects at the TeV scale and type-I corrections to a type-II dominant seesaw for neutrino masses. This is a single-step breaking model with SUSY SO(10) broken at the Grand Unified Theory (GUT)-scale of 2x10^16 GeV to the Minimal Supersymmetric Standard Model (MSSM). The minimal model has only 11 parameters, and therefore, the charged fermion fits predict the masses (up to an overall scale) and mixings in the neutrino sector. We present correlations for the different predictions in the neutrino mixing parameters. The recent experimental "large" \theta_{13} value of \sim 9 degrees can be obtained by a simple extension of the minimal model. We also find that proton decay mode p -> K^+\bar{\nu}_\mu has a partial lifetime of \sim10^34 yrs, which is within reach of the next round of planned proton decay searches. The successful fit for fermion masses requires the Higgs mass to be below 129 GeV in this model. If the Higgs mass lies between 120-128 GeV, as suggested by the recent LHC data, we find a lower limit on the light stop mass of 755 (211) GeV for \mu>0 (<0).