Quasi degenerate Neutrino Masses with Universal Strength Yukawa Couplings

Abstract

A simple ansatz is proposed for neutrino and charged lepton mass matrices, within the framework of universal strength for Yukawa couplings. In this framework all Yukawa couplings have equal moduli and the flavour dependence is only in their phases. We take into account the solar neutrino deficit and the atmospheric neutrino anomaly, assuming three neutrino families only. The ansatz leads in a natural way to small mixing involving neutrinos of quasi degenerate masses, as required to explain the solar neutrino deficit in the nonadiabatic MSW solution, while having the large mixing necessary to explain the atmospheric neutrino anomaly.