Fermion masses in E6 grand unification with family permutation symmetries
نویسنده
چکیده
Neutrino masses have been extensively studied in the context of discrete symmetries. A family permutation symmetry easily explains all neutrino oscillations and their mixing angles. However it is not obvious the embedding of such symmetry in a grand unified theory where all fermions live in the same representation. We show that it is possible to embed such a horizontal discrete symmetry in a grand unified theory. We discuss an E6 GUT model as in [1], but differently from [1], we take the SM Higgs doublet in the 351 to have (+3,+5) charges with respect the additional U(1)r × U(1)t. This choice makes possible two different horizontal symmetry breaking patterns and a distinction between neutrinos and the rest of matter fermions.
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