title: Dirac neutrino masses with planck scale lepton number violation.
abstract: It is shown how pure Dirac neutrino masses can naturally occur at low energies even in the presence of Planck scale lepton number violation. In a 5D setting this is achieved by explicitly breaking the lepton number on the Planck brane while the right-handed neutrino is localized on the TeV brane. A small wave function overlap then naturally leads to a small Dirac Yukawa coupling. In the 4D dual description the right-handed neutrino is identified as a composite CFT bound state and lepton number violation is highly suppressed by CFT operators with large anomalous dimensions.
authors.affiliation: School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Tony
authors.initials: T
authors.lastname: Gherghetta