Lepton masses and mixing in $SU(3)_{C}\otimes SU(3)_{L}\otimes U(1)_{X}$ models with a $S_3$ flavor symmetry

Understand

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.