Lepton flavor violation in the Randall-Sundrum model with bulk neutrinos

Abstract

Lepton flavor violation in the Randall-Sundrum model with bulk neutrinos is considered. Grossman and Neubert recently proposed that the existence of tiny neutrino masses and large mixing could be explained by the presence of the bulk neutrinos in the Randall-Sundrum background. Since the zero mode wave functions of the bulk neutrinos are localized on Planck brane, the Dirac Yukawa couplings on our brane are exponentially suppressed enough to generate tiny neutrino masses. However, the existence of Kaluza-Klein modes of these bulk neutrinos enhance lepton flavor violating processes such as μ→ eγ, from which lower bounds on their masses can be derived. We find that the first KK mode must be heavier than 25 TeV if all the neutrino Yukawa couplings are of order unity, which requires a fine-tuning for the Higgs mass parameter.