General lepton mixing in holographic composite Higgs models

Abstract

We introduce a scenario of lepton mixing in holographic composite Higgs models based on non-abelian discrete symmetries of the form G f = X × Z N , broken to Z 2 × Z 2 × Z N in the elementary sector and to $ Z_N^{{(D)}} $ in the composite sector with $ Z_N^{{(D)}} $ being the diagonal subgroup of a Z N ⊂ X and the external Z N . By choosing X = Δ(96) or Δ(384), a non-vanishing θ13 of order 0.1 is naturally obtained. We apply our considerations to a 5D model in warped space for the particular cases of X = S 4 , A 5 , Δ(96) and Δ(384) and N = 3 or 5. Lepton flavour violating processes and electric dipole moments are well below the current bounds, with the exception of μ → eγ that puts a very mild constraint on the parameter space of the model, for all presented choices of G f .