Yukawa Sector of Minimal SO(10) Unification

TL;DR

This paper presents a minimal SO(10) model with real Higgs fields that successfully fits all fermion masses and mixings, including neutrinos, using a limited set of parameters and an intermediate Pati-Salam symmetry.

Contribution

It introduces a novel SO(10) Yukawa sector with real Higgs fields, reducing complexity and external symmetries, while maintaining predictive power for fermion masses and proton decay.

Findings

Achieves a good fit to fermion masses and mixings.

Predicts specific proton decay modes and branching ratios.

Unifies gauge couplings with an intermediate Pati-Salam scale.

Abstract

We show that in SO(10) models, a Yukawa sector consisting of a real $10_H$, a real $120_H$ and a complex $126_H$ of Higgs fields can provide a realistic fit to all fermion masses and mixings, including the neutrino sector. Although the group theory of SO(10) demands that the $10_H$ and $120_H$ be real, most constructions complexify these fields and impose symmetries exterior to SO(10) to achieve predictivity. The proposed new framework with real $10_H$ and real $120_H$ relies only on SO(10) gauge symmetry, and yet has a limited number of Yukawa parameters. Our analysis shows that while there are restrictions on the observables, a good fit to the entire fermion spectrum can be realized. Unification of gauge couplings is achieved with an intermediate scale Pati-Salam gauge symmetry. Proton decay branching ratios are calculable, with the leading decay modes being $p \rightarrow \overline{\nu} \pi^+$ and $p \rightarrow e^+ \pi^0$.