Inverse tri-bimaximal type-III seesaw and lepton flavor violation

TL;DR

This paper introduces a low-scale inverse type-III seesaw model with A4 flavor symmetry, predicting observable lepton flavor violation and accessible new fermions at the LHC, while naturally explaining small neutrino masses.

Contribution

It develops a novel inverse type-III seesaw framework with A4 symmetry, linking neutrino mass generation to lepton flavor violation and collider phenomenology.

Findings

Predicts sizable LFV three-body decays at tree level

Anticipates observable radiative decays and mu-e conversion

Suggests new fermions are accessible at the LHC

Abstract

We present a type-III version of inverse seesaw or, equivalently an inverse version of type-III seesaw. Naturally small neutrino masses arise at low-scale from the exchange of neutral fermions transforming as hyperchargeless SU(2) triplets. In order to implement tri-bimaximal lepton mixing we supplement the minimal SU(3)xSU(2)xU(1) gauge symmetry with an A4-based flavor symmetry. Our scenario induces lepton flavour violating (LFV) three body decays that can proceed at the tree level, while radiative li to lj gamma decays and mu-e conversion in nuclei are also expected to be sizeable. LFV decays are related by the underlying flavor symmetry and the new fermions are also expected to be accessible for study at the Large Hadron Collider (LHC).