Fermion mixing in an S3 model with three Higgs doublets

We present a brief overview of a unified treatment of masses and mixings of quarks and leptons, as a realization of an S3-flavour permutational symmetry in an extension of the Standard Model. In order to leave S3 as an exact flavour symmetry two extra Higgs fields, SU(2)L doublets, are added. In this model, the mass matrices of the fermions are reparametrized in terms of their eigenvalues allowing us to derive exact, explicit analytical expressions for the mixing matrices, VthCKM and UthPMNS, as functions of the quark and lepton masses, respectively. In both the quark and lepton sectors a χ2 fit of the theoretical expressions to the experimentally determined values of the mixing angles yields results in excellent agreement with the most recent experimental data on quarks and leptons