Natural neutrino sector in a 331-model with Froggatt-Nielsen mechanism

TL;DR

This paper extends a 331-model with Froggatt-Nielsen mechanism to include right-handed neutrinos, demonstrating a seesaw mechanism that explains fermion mass hierarchies and the number of families.

Contribution

It introduces a 331-model with Froggatt-Nielsen mechanism and right-handed neutrinos, realizing a seesaw mechanism near the symmetry-breaking scale.

Findings

Seesaw mechanism is realized within the model.

The model explains fermion mass hierarchies.

The number of fermion families is accounted for.

Abstract

The extensions of the Standard Model based on the $SU(3)_c\times SU(3)_L\times U(1)_X$ gauge group (331-models) have been advocated to explain the number of fermion families in nature. It has been recently shown that the Froggatt-Nielsen mechanism, a popular way to explain the mass hierarchy of the charged fermions, can be incorporated into the 331-setting in an economical fashion (FN331). In this work we extend the FN331-model to include three right-handed neutrino singlets. We show that the seesaw mechanism is realized in this model. The scale of the seesaw mechanism is near the $SU(3)_L\times U(1)_X$-breaking scale. The model we present here simultaneously explains the mass hierarchy of all the fermions, including neutrinos, and the number of families.