Edge of a cliff

TL;DR

This paper explores neutrino flavor structures using minimal assumptions, identifying specific mass matrix patterns compatible with current experimental data and predicting potential exclusions based on upcoming measurements.

Contribution

It introduces nine textures of Dirac neutrino mass matrices within an Occam's razor framework and analyzes their compatibility with neutrino mass hierarchies and experimental constraints.

Findings

Two patterns can realize both normal and inverted hierarchies.

Normal hierarchy scenario may be excluded by CP violation measurements.

Inverted hierarchy scenario may be excluded by neutrinoless double beta decay experiments.

Abstract

We discuss the neutrino flavor structures in the Occam's razor approach for the Dirac neutrino mass matrices. We assume that the charged lepton mass matrix takes a diagonal base, while the right-handed Majorana neutrino mass matrix is also diagonal and we consider nine patterns of the four zero textures for the Dirac neutrinos mass matrices. We numerically analyze the left-handed Majorana neutrino mass matrices for nine patterns of the Dirac neutrino mass matrices and we found two interesting patterns where both normal and inverted neutrino mass hierarchies can be realized. We also found if the neutrino mass is normal hierarchy, this scenario will be likely to be excluded by the measurements of the Dirac CP violating phase in the T2K and NO$\nu $A neutrino experiments, for instance. On the other hand, if the neutrino mass is inverted hierarchy, this scenario will be also likely to be excluded by the measurements of neutrinoless double beta decay experiments, e.g., KamLAND-Zen experiment.