Neutrino Mass Mechanisms in 3-3-1 Models: A Short Review

Abstract

In this study we review some mechanisms that provide light neutrinos in the framework of 3-3-1 gauge models without exotic leptons. In regard to the minimal 3-3-1 model, we call the attention to the fact that the perturbative regime of the model goes until 5 TeV. This requires alternative mechanisms in order to generate light neutrinos. In this review we discuss two mechanisms capable of generating light neutrinos in the framework of the minimal 3-3-1 model. In regard to the 3-3-1 model with right-handed neutrinos, we call the attention to the fact that in it mechanisms that generate light left-handed neutrinos also generate light right-handed neutrinos. Finally, we call the attention to the fact that the 3-3-1 model with right-handed neutrinos accommodate naturally the inverse seesaw mechanism.

Constraining flavor changing interactions from LHC Run-2 dilepton bounds with vector mediators

“…This is problematic because one cannot explain the three mass differences observed in the neutrino oscillation data [85][86][87]. There are ways to generate neutrino masses in agreement with data through effect effective operators [88,89], or by adding extra scalar to incorporate an inverse seesaw mechanism [90,91] with no prejudice to our reasoning which is concentrated on gauge interactions. In this symmetry breaking pattern the 125 GeV higgs mass is easily achieved and the SM gauge boson masses correctly obtained with,…”

A variant of 3-3-1 model for the generation of the SM fermion mass and mixing pattern

“…However, the observed pattern of fermion masses and mixings was not addressed at that time due to the unexplained huge hierarchy among the Yukawa couplings [122,129,134]. Here we propose the first renormalizable extension of the 3-3-1 model with the parameter…”

Lepton number violation in 331 models

“…Note that conventions in the literature vary regarding the signs in front of some of the triplet components 3 i , since these might change with a rephasing of fields components. However, the 1 √ 2 factors cannot be absorbed, so the expression in equation (34) for the sextet differs in a material way from the one used in [13,17,66], for example, agreeing instead with [16]. 10 Finally, we consider what happens to gauge bosons W L,i (i = 1, · · · 8) which are in the adjoint representation (8) of SU (3) L .…”

“…These SU (3) C × SU (3) L × U (1) X (331) models have received considerable attention in connection with various topics: neutrino mass generation [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], flavour symmetries [32][33][34][35][36][37][38][39][40][41][42][43], quark flavour observables [44][45][46][47][48][49][50][51] or the recent LHC diphoton excess [52][53][54][55][56][57], among others. Underpinning this interest is the fact that the 331 to 321 symmetry breaking energy scale can be of the TeV order, hence it could possibly be explored at the LHC; see for example [58][59]…”