Realizing Tri-bimaximal Mixing in Minimal Seesaw Model with S4 Family Symmetry

Understand

In this paper, we realize the tri-bimaximal mixing in the lepton sector in the context of minimal seesaw in which only two right-handed neutrinos are introduced, with the discrete group $S4$ as the family symmetry.

• In order to constrain the form of superpotential, a $Z3$ symmetry is also introduced.
• In the model, the mass matrices for charged leptons and right-handed neutrinos are diagonal.
• The unitary matrix that diagonalizes the light Majorana neutrino mass matrix is exact tri-bimaximal at LO, and is corrected by small quantities of $\mathcal{O}(0.01)$ at NLO.