Proton Decay and Flavor Violating Thresholds in SO(10) Models

TL;DR

This paper explores how threshold effects in supersymmetric SO(10) models can suppress proton decay and induce flavor violation, aligning grand unification with observed neutrino masses and fermion mass unification.

Contribution

It demonstrates a simple threshold mechanism that raises Higgsino and GUT scales, addressing proton decay suppression and flavor violation in SO(10) models.

Findings

Threshold effects can raise the GUT scale to 0^{17} GeV.

Certain SO(10) fields induce flavor violation mainly in the quark sector.

b- au unification is achievable with intermediate eta values.

Abstract

Discovery of neutrino mass has put the spotlight on supersymmetric SO(10) as a natural candidate for grand unification of forces and matter. However, the suppression of proton decay is a major problem in any supersymmetric grand unified models. In this paper we show how to alleviate this problem by simple threshold effect which raises the colored Higgsino masses and the grand unification scale to \gtrsim 10^{17} GeV. There exist only four types of fields arising from different SO(10) representations which can generate this kind of threshold effects. Some of these fields also generate a sizable flavor violation in the quark sector compared to the lepton sector. The b-\tau unification can work in these types of models even for intermediate values of tan\beta.