Neutrino Mass Matrices with Two Vanishing Elements/Cofactors

TL;DR

This paper analyzes how specific neutrino mass matrix textures with two zeros or vanishing cofactors align with recent experimental data, revealing patterns and preferences in neutrino oscillation parameters and CP violation phases.

Contribution

It compares predictions of different texture classes for neutrino parameters, highlighting similarities, differences, and the impact of mass hierarchy on CP phase predictions.

Findings

Classes B1/B2 and B5/B6 have similar oscillation predictions.

A shift in CP phase quadrant is favored for inverted hierarchy with large θ13.

No shift in CP phase quadrant is observed for normal hierarchy.

Abstract

We study the phenomenological implications of the recent neutrino data for class B of two texture zeros and two vanishing cofactors for Majorana neutrinos in the flavor basis. We find that classes $B_{1}$($B_2$) of two texture zeros and classes $B_5$($B_6$) of two vanishing cofactors have similar predictions for neutrino oscillation parameters for the same mass hierarchy. Similar predictions for classes $B_3$($B_4$) of two texture zeros and classes $B_3$($B_4$) of two vanishing cofactors are expected. However, a preference for a shift in the quadrant of the Dirac-type CP violating phase($\delta$) in contrast to the earlier analysis has been predicted for a relatively large value of the reactor neutrino mixing angle($\theta_{13}$) for class B of two texture zeros and two vanishing cofactors for an inverted mass spectrum. No such shift in the quadrant of $\delta$ has been found for the normal mass spectrum.