Leptons and quarks from a discrete flavor symmetry

We propose a new model of leptons and quarks based on the discrete flavor symmetry T', the double covering of A(4), in which the hierarchies of charged fermion masses and the mildness of neutrino masses are responsible for Higgs scalars. After spontaneous breaking of flavor symmetry, with the constraint of renormalizability in the Lagrangian, the leptons have m(e) = 0 and the quarks have the Cabibbo-Kobayashi-Maskawa mixing angles theta(q)(12) = 13 degrees, theta(q)(23) = 0 degrees and theta(q)(13) = 0 degrees. Thus, certain effective dimension-5 operators are introduced, which induce m(e) not equal 0 and lead the quark mixing matrix to the Cabibbo-Kobayashi-Maskawa one in the form. On the other hand, the neutrino Lagrangian still keeps renormalizability. For completeness, we show a numerical analysis: in the lepton sector, only normal mass hierarchy is permitted within 3 sigma experimental bounds with the prediction of both large deviations from maximality in the atmospheric mixing angle theta(23) and the measured values of the reactor angle. So, future precise measurements of theta(23), whether theta(23) -> 45 degrees or vertical bar theta(23) -> 45 degrees vertical bar -> 5 degrees, will either exclude or favor our model. Together with it, our model makes predictions for the Dirac CP phase, which is almost compatible with the global analysis in 1 sigma experimental bounds. Moreover, we show the effective mass vertical bar m(ee)vertical bar measurable in neutrinoless double beta decay to be in the range 0.04 less than or similar to vertical bar m(ee)vertical bar[eV] < 0.11, which can be tested in near future neutrino experiments.