Leptoquarks with Exactly Stable Protons

TL;DR

This paper proposes a new mechanism involving gauge symmetries and scalar condensates that ensures proton stability at all orders, addressing flavor anomalies and integrating with grand unified theories.

Contribution

It introduces a novel approach using a lepton-flavored gauge symmetry and discrete symmetries to guarantee proton stability and explain flavor anomalies.

Findings

Proposes a gauge symmetry-based mechanism for proton stability.

Connects the mechanism to flavor anomalies and grand unified theories.

Abstract

We explore a novel mechanism to restrict TeV-scale leptoquark interactions and render the proton exactly stable to all orders in the effective field theory expansion. A scalar condensate breaks a lepton-flavoured $\mathrm{U}(1)_X$ gauge symmetry in the ultraviolet and generates neutrino masses, leaving a discrete $\mathbb{Z}_9$ or $\mathbb{Z}_{18}$ gauge symmetry in the infrared, forbidding $\Delta B = 1$ processes. This provides an elegant framework to address the flavour anomalies and can be adapted to many other new-physics models. The $ \mathrm{U}(1)_X $ can emerge from a gauge-flavour unified $ \mathrm{SU}(12) \times \mathrm{SU}(2) \times \mathrm{SU}(2) $ theory at even higher energies.