General Lepton Mixing in Holographic Composite Higgs Models

TL;DR

This paper proposes a new lepton mixing scenario within holographic composite Higgs models using non-abelian discrete symmetries, achieving realistic mixing angles and consistent flavor violation constraints.

Contribution

It introduces a novel symmetry-breaking framework in holographic composite Higgs models that naturally produces a non-zero theta_{13} mixing angle.

Findings

Achieves theta_{13} of order 0.1 naturally.

Lepton flavor violation processes are below current experimental bounds.

Mu -> e gamma decay constrains the model mildly.

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 x Z_N, broken to Z_2 x Z_2 x 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 contained in X and the external Z_N. By choosing X = Delta(96) or Delta(384), a non-vanishing theta_{13} 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, Delta(96) and Delta(384) and N=3 or 5. Lepton flavour violating processes and electric dipole moments are well below the current bounds, with the exception of mu -> e gamma that puts a very mild constraint on the parameter space of the model, for all presented choices of G_f.