S-3 symmetry and tri-bimaximal mixing

摘要

The near maximal value for the atmospheric neutrino mixing angle together with the fact that the solar mixing angle satisfies the relation sin(2) theta circle dot similar or equal to 1/3 is the basis for the so-called tri-bimaximal mixing when theta(13) = 0. In this Letter, we explore the possibility that tri-bimaximal mixing is an indication of a softly broken higher leptonic symmetry S-3, the permutation of three lepton families that embeds the mu-tau exchange symmetry of leptons. (c) 2006 Published by Elsevier B.V.