Proton decay suppression in a supersymmetric SO(10) model

TL;DR

This paper introduces a novel suppression mechanism for proton decay in a supersymmetric SO(10) model, utilizing an intermediate VEV generated by an anomalous U(1) symmetry, maintaining gauge coupling unification.

Contribution

It proposes a new suppression mechanism for proton decay operators using an intermediate VEV, compatible with realistic fermion masses and gauge unification.

Findings

Proton decay amplitudes are significantly suppressed by the introduced VEV.

The model predicts a tanβ of order one under minimal fine-tuning.

The mechanism maintains gauge coupling unification with an intermediate VEV.

Abstract

We propose a mechanism for sufficient suppression of dimension-5 operators for proton decay in a supersymmetric SO(10) model. This mechanism is analogue to the double seesaw mechanism in studying neutrino masses. Only an intermediate VEV instead of an intermediate scale is required so that gauge coupling unification is maintained. The VEV is generated by introducing an anomalous U(1) symmetry whose breaking is at higher scale. The proton decay amplitudes are suppressed by this VEV over the GUT scale. We use $\textbf{45+54}$ in breaking GUT symmetry. $\textbf{120}$ is included so that fermion sector is fully realistic. Assuming a minimal fine-tuning in the Higgs doublet sector, $\textrm{tan}\beta$ of order one is predicted.