Revisiting bimaximal neutrino mixing in a model with S-4 discrete symmetry

In view of the fact that the data on neutrino mixing are still compatible with a situation where Bimaximal mixing is valid in first approximation and it is then corrected by terms of (λC) (with λC being the Cabibbo angle), arising from the diagonalization of the charged lepton masses, such that δsin2θ12 ~ sinθ13 ~ (λC) while δsin2θ23 ~ (λC2), we construct a model based on the discrete group S4 where those properties are naturally realized. The model is supersymmetric in 4-dimensions and the complete flavour group is S4 × Z4 × U(1)FN, which also allows to reproduce the hierarchy of the charged lepton spectrum. The only fine tuning needed in the model is to reproduce the small observed value of r = Δm2sun/Δm2atm. Once the relevant parameters are set to accommodate r then the spectrum of light neutrinos shows a moderate normal hierarchy and is compatible, within large ambiguities, with the constraints from leptogenesis as an explanation of the baryon asymmetry in the Universe.