Seesaw Scale in the Minimal Renormalizable SO(10) Grand Unification

TL;DR

This paper demonstrates that certain minimal SO(10) grand unified models with specific Higgs sectors can achieve stable unification with high B-L breaking scales, supporting realistic neutrino mass mechanisms and testability at future experiments.

Contribution

It shows that the minimal renormalizable SO(10) model with 45_H+126_H Higgs fields can have stable unification at high scales, contrary to previous beliefs.

Findings

Stable unification with B-L scale up to 10^14 GeV.

Supports canonical seesaw mechanism for neutrino masses.

Potential testability at Hyper-Kamiokande.

Abstract

Simple SO(10) Higgs models with the adjoint representation triggering the grand-unified symmetry breaking, discarded a long ago due to inherent tree-level tachyonic instabilities in the physically interesting scenarios, have been recently brought back to life by quantum effects. In this work we focus on the variant with 45_H+126_H in the Higgs sector and show that there are several regions in the parameter space of this model that can support stable unifying configurations with the B-L breaking scale as high as 10^14 GeV, well above the previous generic estimates based on the minimal survival hypothesis. This admits for a renormalizable implementation of the canonical seesaw and makes the simplest potentially realistic scenario of this kind a good candidate for a minimal SO(10) grand unification. Last, but not least, this setting is likely to be extensively testable at future large-volume facilities such as Hyper-Kamiokande.