The 3-3-1 model with exotic electric charges, right-handed neutrinos with type-I+II seesaw mechanism and its effects on LFV

TL;DR

This work develops a modified 3-3-1 model with exotic charges that integrates a combined type I+II seesaw mechanism and a $Z_{4}$ symmetry to address LFV and neutrino masses. The authors construct anomaly-free fermion content, implement a two-stage spontaneous symmetry breaking, and derive detailed mass matrices for leptons, quarks, and heavy exotics, including a $6\times6$ neutrino sector. Using SARAH and SPheno, they obtain SM-like masses and mixings that match data and predict LFV branching ratios; notably, the $Br(\\mu \rightarrow e\gamma)$ and related channels are reported at values closer to experimental limits than previous 3-3-1 estimates. The results demonstrate a phenomenologically viable, testable framework at TeV scales with rich scalar and gauge spectra amenable to collider probes and flavor tests.

Abstract

In this research, we propose a modified version of the 3-3-1 model, incorporating a type I+II seesaw mechanism and Z4 discrete symmetry, as a framework for investigating lepton flavor-violating (LFV) decays. This model successfully yields the left-handed neutrinos mass square difference in the eV scale, with specific values of mass square differences; and generates mixing angles that align with experimental data. Furthermore, we develop SARAH and SPheno algorithms tailored for our modified model, enabling us to estimate the magnitude of LFV observables. Our calculations indicate favorable results for various LFV branching ratios. These findings demonstrate improved agreement with experimental measurements compared to previously reported results, which typically fall within the range of 10^-2 to 10^-6.