Fermion masses and mixings and charged lepton flavor violation in a 3-3-1 model with inverse seesaw

TL;DR

This paper extends a 3-3-1 gauge model with flavor symmetries to explain fermion masses, mixings, and charged lepton flavor violation, predicting observable rare decay rates and addressing neutrino mass generation via inverse seesaw.

Contribution

It introduces a novel 3-3-1 model with multiple discrete symmetries, successfully reproducing fermion mass hierarchies and mixing patterns, and analyzing lepton flavor violation within this framework.

Findings

Reproduces SM fermion mass hierarchies and mixings.

Predicts charged lepton flavor violating decay rates within experimental reach.

Identifies parameter space consistent with current experimental constraints.

Abstract

We present a extension of the 3-3-1 gauge model supplemented by an $A_4$ flavor symmetry and cyclic discrete symmetries, including $Z_2$, $Z_2'$, $Z_3$, $Z_4$, $Z_7$ and $Z_{10}$. The model successfully reproduces the observed SM fermion mass hierarchies and mixing patterns in quark and lepton sectors. The smallness of the active neutrino masses is explained through an inverse seesaw mechanism, enabled by the introduction of right-handed and sterile Majorana neutrinos. In the quark sector, flavor-changing neutral currents (FCNCs) arise at tree level exclusively for up-type quarks via the new heavy neutral gauge boson exchange, leading to strong constraints from $D^0$ - $\bar{D}^0$ mixing. The charged lepton sector exhibits sizeable flavor-violating effects, especially in the $\mu \rightarrow e \gamma$ decay, mediated by loops involving heavy neutrinos, new charged gauge bosons as well as charged scalars. We perform a detailed numerical fit of fermion masses and mixing parameters and identify viable regions of parameter space consistent with experimental data on CKM and PMNS mixing matrices. The model predicts branching ratios for charged lepton flavor violating decays and $\mu$-$e$ conversion rates within the sensitivity of future experiments.