Majorana Neutrino Mass Matrices with a Texture Zero and a Cofactor Zero under Current Experimental Texts

Abstract

The Majorana neutrino mass textures with a texture zero and a vanishing cofactor are reconsidered in the light of current experimental results. A numerical and systematic analysis is carried out for all viable patterns. In particular, we focus on the phenomenological implication of correlations between three mixing angle (especially for $θ_{23}$), Dirac CP-violating phase $δ$, the effective Majorana neutrino mass $m_{ee}$. We demonstrated that the correlations between these variables play an important role in the model selection and can be measured in future long-baseline oscillation and neutrinoless double beta decay. Among the six viable patterns, it is the type-III with normal hierarchy and type-VI with inverted hierarchy that have the parameter space where the atmospheric neutrino mixing angle $θ_{23}$ is less then maximal and the Dirac CP-violating phase covers its best-fit value.