摘要

We propose a model of quark and lepton mixing based on the tetrahedral A(4) family symmetry with quark-lepton unification via the tetra-colour Pati-Salam gauge group SU(4)(PS), together with SU(2)(L) x U(1)(R). The "tetra-model" solves many of the flavour puzzles and remarkably gives ten predictions at leading order, including all six PMNS parameters. The Cabibbo angle is approximately given by theta(C) approximate to 1/4, due to the tetra-vacuum alignment (1, 4, 2), providing the Cabibbo connection between quark and lepton mixing. Higher order corrections are responsible for the smaller quark mixing angles and CP violation and provide corrections to the Cabibbo and lepton mixing angles and phases. The tetra-model involves an SO(10)-like pattern of Dirac and heavy right-handed neutrino masses, with the strong up-type quark mass hierarchy cancelling in the see-saw mechanism, leading to a normal hierarchy of neutrino masses with an atmospheric angle in the first octant, theta(l)(23) = 40 degrees +/- 1 degrees, a solar angle theta(l)(12) = 34 degrees +/- 1 degrees, a reactor angle theta(l)(13) = 9.0 degrees +/- 0.5 degrees, depending on the ratio of neutrino masses m(2)/m(3), and a Dirac CP violating oscillation phase delta(l) = 260 degrees +/- 5 degrees.

  • 出版日期2014-1-22