Lepton number violation in 331 models

TL;DR

This paper reviews 331 gauge models, focusing on lepton number violation and modifications to explain neutrino masses, highlighting their potential and limitations in beyond Standard Model physics.

Contribution

It provides a comprehensive review of lepton number violation in 331 models and discusses modifications to incorporate realistic neutrino masses.

Findings

Identifies sources of lepton number violation in 331 models.

Discusses model modifications for neutrino mass generation.

Highlights unresolved issues in lepton number and neutrino mass explanations.

Abstract

Different models based on the extended $SU(3)_{C}\times SU(3)_{L}\times U(1)_{X}$ (331) gauge group have been proposed over the past four decades. Yet, despite being an active research topic, the status of lepton number in 331 models has not been fully addressed in the literature, and furthermore many of the original proposals can not explain the observed neutrino masses. In this paper we review the basic features of various 331 models, focusing on potential sources of lepton number violation. We then describe different modifications which can be made to the original models in order to accommodate neutrino (and charged lepton) masses.