Lepton-flavour violation in a Pati-Salam model with gauged flavour symmetry

TL;DR

This paper presents a Pati-Salam model with gauged flavour symmetry that explains charged lepton masses and predicts significant lepton-flavour violation, analyzed through processes like mu to e gamma and muon conversion.

Contribution

It introduces a renormalisable Pati-Salam model with gauged flavour symmetry and heavy fermions, providing a framework for lepton-flavour violation predictions.

Findings

Model generates realistic charged lepton masses.

Predicts sizeable lepton-flavour violating processes.

Analyzes implications for muon to electron transitions.

Abstract

Combining Pati-Salam (PS) and flavour symmetries in a renormalisable setup, we devise a scenario which produces realistic masses for the charged leptons. Flavour-symmetry breaking scalar fields in the adjoint representations of the PS gauge group are responsible for generating different flavour structures for up- and down-type quarks as well as for leptons. The model is characterised by new heavy fermions which mix with the Standard Model quarks and leptons. In particular, the partners for the third fermion generation induce sizeable sources of flavour violation. Focusing on the charged-lepton sector, we scrutinise the model with respect to its implications for lepton-flavour violating processes such as $\mu \rightarrow e\gamma$, $\mu\rightarrow 3e$ and muon conversion in nuclei.