Resonant Dirac leptogenesis on throats

Abstract

We consider resonant Dirac leptogenesis in a geometry with three five-dimensional throats in the flat limit. The baryon asymmetry in the universe is generated by resonant decays of heavy Kaluza-Klein scalars that are copies of the standard model Higgs. Discrete exchange symmetries between the throats are responsible for establishing two key features of the model. First, they ensure a near degeneracy of the scalar masses and thus a resonant decay of the scalars. This allows for Dirac leptogenesis at low energies close to the TeV scale. Second, the discrete symmetries connect the observed baryon asymmetry with the Yukawa couplings of the low-energy theory. As a consequence, we obtain correlations between the low-energy leptonic mixing parameters and the Dirac CP phase that can be tested at future neutrino oscillation experiments such as neutrino factories.