Neutrino masses in a 331 model with right-handed neutrinos without doubly charged Higgs

TL;DR

This paper explores a 331 gauge model with right-handed neutrinos that naturally generates small neutrino masses through double and inverse seesaw mechanisms, avoiding the need for doubly charged Higgs fields.

Contribution

It introduces a 331 model with three scalar triplets and neutral fermion singlets, demonstrating how to obtain small neutrino masses without scalar sextets or doubly-charged Higgs.

Findings

Neutrino spectrum includes light, heavy, and very heavy states with a large Majorana mass matrix.

Alternative scenario with small or zero Majorana mass yields pseudo-Dirac or Dirac heavy neutrinos.

Model accommodates TeV-scale heavy neutrinos alongside active light neutrinos.

Abstract

We discuss a 331 model with three scalar triplets and neutral fermion singlets. We show that in the 331 model with right-handed neutrinos, it is possible to obtain small active neutrino masses via the double and inverse seesaw mechanisms, without the use of scalar sextets or triplets with doubly-charged Higgs. Two types of models are discussed. If we have a large Majorana mass matrix for the singlets, the spectrum of neutrinos presents light, heavy and very heavy masses. The other possibility is a small (zero) Majorana mass matrix, which leads to pseudo-Dirac (Dirac) heavy neutrinos in the TeV scale, in addition to the active light neutrinos