Speaker
Description
We investigate the possibility of two-zeros in inverse neutrino mass matrix ($M_{\nu}^{-1}$) in light of "dark" large mixing angle (dark-$\theta_{12}$) solution to the solar neutrino problem where solar mixing angle lies in the second octant ($\sin^{2}{\theta_{12}}\simeq 0.7$). The zeros in right-handed Majorana neutrino mass matrix $M_{R}$ corresponds to the zeros in $M_{\nu}^{-1}$ if Dirac and charged lepton mass matrices are diagonal. Out of fifteen possible two-zero textures, only seven are found to be consistent with dark-$\theta_{12}$ solution. All the textures with vanishing (1,1) element are found to be inconsistent with dark-$\theta_{12}$ solution. We, also, obtained predictions of the model for $0\nu\beta\beta$ amplitude $|M_{ee}|$. For five out of seven allowed textures, the predicted 3$\sigma$ lower bound on $0\nu\beta\beta$ amplitude $|M_{ee}|$ is $\mathcal{O}(10^{-2})$ which is within the sensitivity reach of $0\nu\beta\beta$ decay experiments like SuperNEMO, KamLAND-Zen, NEXT and nEXO. Furthermore, these textures are found to be necessarily $CP$-violating. Within Type-I seesaw setting, we have shown that the allowed $M_{\nu}^{-1}$ textures can be realized using $A_{4}$ discrete flavor symmetry wherein the standard model particle content has been enlarged with three right-handed neutrinos and a scalar singlet field.
| Session | Neutrino Physics |
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