Scotogenic S3 symmetric generation of realistic neutrino mixing

Abstract

Realistic neutrino mixing is achieved at one-loop level radiatively using $S3\times Z_2$ symmetry. The model comprises of two right-handed neutrinos, maximally mixed to produce the structure of the left-handed Majorana neutrino mass matrix characterized by $\theta_{13}=0$, $\theta_{23}=\pi/4$ and any value of $\theta_{12}^0$ particular to the Tribimaximal (TBM), Bimaximal (BM) and Golden Ratio (GR) or other mixings. A small deviation from this maximal mixing between the two right-handed neutrinos could generate non-zero $\theta_{13}$, shifts of the atmospheric mixing angle $\theta_{23}$ from $\pi/4$ and also could correct the solar mixing angle $\theta_{12}$ by a small amount altogether in a single step. In this scotogenic mechanism of generating non-zero $\theta_{13}$ by shifting from maximal mixing in the right-handed neutrino sector, two $Z_2$ odd inert scalar $SU(2)_L$ doublets were used, the lightest of which can serve as a dark matter candidate.