O ct 2 00 6 On the Fukugita-Tanimoto-Yanagida Ansatz with Partially Non-degenerate Right-handed Majorana Neutrinos

Taking three right-handed Majorana neutrino masses Mi to be partially non-degenerate, we make a new analysis of the Fukugita-Tanimoto-Yanagida ansatz and confront it with current neutrino oscillation data. We determine the parameter space for cases (A) M3 = M2 6= M1, (B) M2 = M1 6= M3 and (C) M1 = M3 6= M2, and examine their respective deviations from the… (More)