S3 symmetry and neutrino masses and mixings

Based on the universal seesaw mass matrix model with the three scalars phi(i), and by assuming S-3 flavor symmetry for the Yukawa interactions, the lepton masses and mixings are investigated systematically. In order to understand the observed neutrino mixing, the charged leptons (e,mu,tau) are regarded as the three objects (e(1),e(2),e(3)) of S-3, while the neutrino mass eigenstates are regarded as the irreducible representation (nu(eta),nu(sigma),nu(pi)) of S-3, where (nu(pi),nu(eta)) and nu(sigma) are a doublet and a singlet, respectively, which are composed of the three objects (nu(1),nu(2),nu(3)) of S-3.