Three-Neutrino Mass Matrices with Two Texture Zeros

Abstract

Out of the fifteen 3 x 3 neutrino mass matrices with two texture zeros seven are compatible with the neutrino oscillation data. While 2 of them correspond to hierarchical neutrino masses and 1 to an inverted hierarchy, the remaining 4 correspond to degenerate masses. Moreover only the first 3 of the 7 mass matrices are compatible with the maximal mixing angle of atmospheric neutrino and hence favoured by data. We give compact expressions for mass matrices in terms of mass eigenvalues and study phenomenological implications for the 7 cases. Similarity of the textures of the neutrino, charged-lepton mass matrices with those of quark mass matrices is also discussed.