# On the Origin of Two-Loop Neutrino Mass from SU(5) Grand Unification

## TL;DR

This paper presents a renormalizable $SU(5)$ grand unified model where neutrino masses arise at the two-loop level, linking them to charged fermion masses and enabling potential experimental tests via proton decay and B-physics anomalies.

## Contribution

The paper introduces a novel $SU(5)$ model that generates neutrino masses at two loops without adding new fermions, connecting neutrino and charged fermion masses.

## Key findings

- Achieves realistic charged fermion masses and mixings.
- Provides gauge coupling unification consistent with proton decay constraints.
- Offers explanations for B-physics anomalies through scalar leptoquarks.

## Abstract

In this work we propose a renormalizable model based on the $SU(5)$ gauge group where neutrino mass originates at the two-loop level without extending the fermionic content of the Standard Model (SM). Unlike the conventional $SU(5)$ models, in this proposed scenario, neutrino mass is intertwined with the charged fermion masses. In addition to correctly reproducing the SM charged fermion masses and mixings, neutrino mass is generated at the quantum level, hence naturally explains the smallness of neutrino masses. In this set-up, we provide examples of gauge coupling unification that simultaneously satisfy the proton decay constraints. This model has the potential to be tested experimentally by measuring the proton decay in the future experiments. Scalar leptoquarks that are naturally contained within this framework can accommodate the recent B-physics anomalies.