A flavor symmetry model for bilarge leptonic mixing and the lepton masses

Abstract

We present a model for leptonic mixing and the lepton masses based on flavor symmetries and higher-dimensional mass operators. The model predicts bilarge leptonic mixing (i.e., the mixing angles θ 12 and θ 23 are large and the mixing angle θ 13 is small) and an inverted hierarchical neutrino mass spectrum. Furthermore, it approximately yields the experimental hierarchical mass spectrum of the charged leptons. The obtained values for the leptonic mixing parameters and the neutrino mass squared differences are all in agreement with atmospheric neutrino data, the Mikheyev–Smirnov–Wolfenstein large mixing angle solution of the solar neutrino problem, and consistent with the upper bound on the reactor mixing angle. Thus, we have a large, but not close to maximal, solar mixing angle θ 12, a nearly maximal atmospheric mixing angle θ 23, and a small reactor mixing angle θ 13. In addition, the model predicts θ 12≃ π 4 −θ 13 .