Large neutrino mixing and normal mass hierarchy: A discrete understanding

We discuss the possibility of flavor symmetries to explain the pattern of charged lepton and neutrino masses and mixing angles. We emphasize what are the obstacles for the generation of an almost maximal atmospheric mixing and what are the minimal ingredients to obtain it. A model based on the discrete symmetry S-3 is constructed, which leads to the dominant mutau-block in the neutrino mass matrix, thus predicting normal hierarchy. This symmetry makes it possible to reproduce current data and predicts 0.01less than or similar totheta(13)less than or similar to0.03 and strongly suppressed neutrinoless 2beta-decay. Moreover, it implies a relation between lepton and quark mixing angles: theta(23)(q)approximate to2(pi/4-theta(23)). The Cabibbo mixing can also be reproduced and theta(13)(q)similar totheta(12)(q)theta(23)(q). S-3 is thus a candidate to describe all the basic features of standard model fermion masses and mixing.