Lepton masses and mixing in $SU(3{)}_C\otimes SU(3{)}_L\otimes U(1{)}_X$ models with a $S_3$ flavor symmetry

Abstract

We propose a model based on the gauge group $SU(3{)}_C\otimes SU(3{)}_L\otimes U(1{)}_X$ with an extra $S_3$ flavor symmetry, which accounts for the lepton masses and mixing. The small active neutrino masses are generated via a double seesaw mechanism. In this scenario, the spectrum of neutrinos presents very light, light and very heavy masses. The model predicts a quasidegenerate normal hierarchy active neutrino mass spectrum and the relation $\Delta m_{21}^2\ll \Delta m_{31}^2$ arises from effective six-dimensional operators. The obtained neutrino mixing parameters are in agreement with the neutrino oscillation experimental data. We find CP violation in neutrino oscillations with a Jarlskog invariant of about $10^{-2}$.

Comments: 14 pages. Version for publication in Physical Review D