Lepton mass and mixing in a Neutrino Mass Model based on $S_4$ flavor   symmetry
  We study a neutrino mass model based on $S_4$ flavor symmetry which accommodates lepton mass, mixing with non-zero $\theta_{13}$ and CP violation phase. The spontaneous symmetry breaking in the model is imposed to obtain the realistic neutrino mass and mixing pattern at the tree- level with renormalizable interactions. Indeed, the neutrinos get small masses from one $SU(2)_L$ doubplet and two $SU(2)_L$ singlets in which one being in $\underline{2}$ and the two others in $\underline{3}$ under $S_4$ with both the breakings $S_{4}\rightarrow S_3$ and $S_{4}\rightarrow Z_3$ are taken place in charged lepton sector and $S_4\rightarrow \mathcal{K}$ in neutrino sector. The model also gives a remarkable prediction of Dirac CP violation $\delta_{CP}=\frac{\pi}{2}$ or $-\frac{\pi}{2}$ in the both normal and inverted spectrum which is still missing in the neutrino mixing matrix. The relation between lepton mixing angles is also represented. 
V. V. Vien
hep-ph