Implications of generalized Frampton-Glashow-YanagidaAnsätzeon neutrino masses and lepton flavor mixing

In the most minimal seesaw model with two heavy right-handed neutrinos, we generalize the Frampton-Glashow-Yanagida Ansatz for the 3×2 Dirac neutrino mass matrix and show that the determinant of the 3×3 light Majorana neutrino mass matrix M always vanishes. Parametrizing M in terms of three neutrino masses, three lepton mixing angles, and three CP-violating phases, we examine all its possible one-zero textures with one vanishing mass eigenvalue. We find that three one-zero patterns of M with m₁=0 and four one-zero patterns of M with m₃=0 are compatible with current neutrino oscillation data. The implications of these phenomenological Ans\"atze on the neutrino mass spectrum and the neutrinoless double beta decay are also discussed.