Power-law enhancement of neutrino mixing angles in extra dimensions

Abstract

We study the renormalization of the llHH-type Majorana neutrino mass operator in a scenario in which there is a compactified extra dimension and the fields involved correspond to only the standard model particles and their Kaluza-Klein excitations. We observe that in a two-flavor scenario, in which one of the neutrinos is necessarily ν_τ, it is indeed possible to generate a large mixing at ~100GeV starting from a very small mixing near the ultraviolet cutoff ~30TeV. In passing, we also derive the Higgs mass upper and lower limits from perturbative unitarity and stability of the potential, respectively.