Two-zero Textures of the Majorana Neutrino Mass Matrix and Current Experimental Tests

TL;DR

This paper systematically studies two-zero textures of the Majorana neutrino mass matrix, identifying compatible patterns with current data, analyzing their stability, and exploring phenomenological implications and flavor symmetry realizations.

Contribution

It provides a comprehensive analysis of viable two-zero textures of M_nu, including stability against quantum corrections and phenomenological implications.

Findings

Seven texture patterns are compatible with experimental data at 3-sigma.

Texture zeros are stable under one-loop quantum corrections.

Permutation symmetries relate different texture patterns.

Abstract

In view of the latest T2K and MINOS neutrino oscillation data which hint at a relatively large theta_13, we perform a systematic study of the Majorana neutrino mass matrix M_nu with two independent texture zeros. We show that three neutrino masses (m_1, m_2, m_3) and three CP-violating phases (delta, rho, sigma) can fully be determined from two neutrino mass-squared differences (delta m^2, Delta m^2) and three flavor mixing angles (theta_12, theta_23, theta_13). We find that seven patterns of M_nu (i.e., A_{1,2}, B_{1,2,3,4} and C) are compatible with current experimental data at the 3-sigma level, but the parameter space of each pattern is more strictly constrained than before. We demonstrate that the texture zeros of M_nu are stable against the one-loop quantum corrections, and there exists a permutation symmetry between Patterns A_1 and A_2, B_1 and B_2 or B_3 and B_4. Phenomenological implications of M_nu on the neutrinoless double-beta decay and leptonic CP violation are discussed, and a realization of those texture zeros by means of the Z_n flavor symmetries is illustrated.