Large lepton mixing angles from a $4\mathbf{+}1$-dimensional $SU\mathbf{(}5\mathbf{)}\mathbf{\ifmmode\times\else\texttimes\fi{}}{A}_{4}$ domain-wall braneworld model

Large lepton mixing angles from a $4 + 1$ -dimensional $S U (5) \times A_{4}$ domain-wall braneworld model

Benjamin D. Callen and Raymond R. Volkas

Phys. Rev. D 86, 056007 – Published 21 September 2012

Abstract

We propose an extension of the $4 + 1$ -dimensional $S U (5)$ domain-wall braneworld of Davies, George and Volkas which includes the addition of a discrete $A_{4}$ flavor symmetry. We show that lepton mixing and light Majorana neutrino masses can be generated from the additional $A_{4}$ physics while at the same time sufficient parameter freedom can be maintained in the charged fermion sector to produce charged fermion masses and quark mixing naturally from the split fermion mechanism. Importantly, we show that the vacuum realignment problem typical of discrete flavor symmetry models of quark and lepton mixing can be solved by separating the appropriate flavons in the extra dimension, leading to exponentially sensitive suppression of the operators responsible for vacuum realignment.