Charged lepton flavour violation from inverse seesaw with flavour and CP symmetries

TL;DR

This paper investigates charged lepton flavor violation within an inverse seesaw model incorporating specific flavor and CP symmetries, analyzing the impact of experimental bounds and future sensitivities on model parameters.

Contribution

It introduces a novel inverse seesaw framework with flavor and CP symmetries, predicting lepton mixing and analyzing experimental constraints on flavor-violating processes.

Findings

Current bounds do not constrain the model's parameter space.

Future experiments could significantly restrict the model.

Heavy sterile states influence light neutrino masses and mixing.

Abstract

We study charged lepton flavour violation in a scenario in which light neutrino masses are generated via the inverse seesaw mechanism with 3+3 gauge singlet fermions, Ni and Sj, i,j=1,2,3. Lepton mixing is predicted with the help of the flavour symmetries Delta (3 n^2) and Delta (6 n^2) combined with CP. In the neutral lepton sector, the non-trivial flavour structure is only encoded in the Dirac neutrino Yukawa matrix (the coupling relating left-handed lepton doublets and gauge singlets Ni). Current experimental bounds on the processes mu -> e gamma, mu -> 3 e, mu-e conversion in nuclei and the tau lepton decays tau -> l gamma and tau -> 3 l, l=e, mu, do not constrain the considered parameter space of this scenario. Prospective limits on the decay mu -> 3 e and mu-e conversion in aluminium instead can markedly reduce the available parameter space. We also comment on the effects of the heavy sterile states on light neutrino masses and lepton mixing.