Charged Lepton Flavour Violating Radiative Decays $\ell_i \to \ell_j + \gamma$ in See-Saw Models with $A_4$ Symmetry

TL;DR

This paper investigates charged lepton flavor violating radiative decays within supersymmetric $A_4$ models incorporating the see-saw mechanism, predicting decay rates under specific model assumptions and minimal supergravity conditions.

Contribution

It provides detailed predictions for LFV decay rates in $A_4$ models with see-saw and mSUGRA, highlighting the impact of specific flavor symmetries on observable processes.

Findings

Predicted decay rates for $ au o au + ext{gamma}$ and others.

Model-specific predictions consistent with current experimental bounds.

Analysis within two explicit $A_4$ model realizations.

Abstract

The charged lepton flavour violating (LFV) radiative decays, $\mu\to e+\gamma$, $\tau\to \mu+\gamma$ and $\tau\to e +\gamma$ are investigated in a class of supersymmetric $A_4$ models with three heavy right-handed (RH) Majorana neutrinos, in which the lepton (neutrino) mixing is predicted to leading order (LO) to be tri-bimaximal. The light neutrino masses are generated via the type I see-saw mechanism. The analysis is done within the framework of the minimal supergravity (mSUGRA) scenario, which provides flavour universal boundary conditions at the scale of grand unification $M_X \approx 2 \times 10^{16}$ GeV. Detailed predictions for the rates of the three LFV decays are obtained in two explicit realisations of the $A_4$ models due to Altarelli and Feruglio and Altarelli and Meloni, respectively.