Bimaximal neutrino mixing and small U-e3 from Abelian flavor symmetry

Abstract

Atmospheric neutrino data strongly suggest a near-maximal nu (mu)-nu (tau) mixing and also solar neutrino data can be nicely explained by another near-maximal nu (e)-nu (mu) or nu (e)-nu (tau) mixing. We examine the possibility that this bimaximal mixing of atmospheric and solar neutrinos arises naturally. while keeping U-e3 and Deltam(sol)(3)/Deltam(atm)(2) small enough, as a consequence of Abelian flavor symmetry. Two simple scenarios ofAbelian flavor symmetry within the supersymmetric framework are considered to obtain the desired form of the neutrino mass matrix and the charged lepton mass matrix parametrized by the Cabibbo angle lambda approximate to 0.2. Future experiments at a neutrino factory measuring the size of U-e3 and the sign of Deltam(32)(2) could discriminate between those scenarios as they predict distinctive values of U-e3 in connection with Deltam(sol)(2)/Deltam(atm)(2) and also with the order of the neutrino mass eigenvalues.