Simple neutrino mass matrix with only two free parameters

Abstract

A simple form of neutrino mass matrix which has only two free parameters is proposed from a phenomenological point of view. Using this mass matrix, we succeed to reproduce all the observed values for the MNS lepton mixing angles and the neutrino mass squared difference ratio. Our model also predicts $\delta_{\nu}= 155^\circ$ for the Dirac CP violating phase in the lepton sector and the effective neutrino mass $\langle m \rangle=6.3\times 10^{-3}$ eV in the neutrinoless double beta decay.