Neutrino Mixing from the Charged Lepton Sector with Sequential Right-Handed Lepton Dominance

Abstract

We systematically analyze the possibility that bi-large lepton mixing originates from the charged lepton sector in models with sequential dominance for the right-handed charged leptons. We derive analytical expressions for the mixing angles and CP phases of the MNS matrix for the case of zero mixing from the neutrino sector, which is arranged for with the help of sequential dominance for the right-handed neutrinos. For small $\theta_{13}$, the two large mixing angles $\theta_{12}$ and $\theta_{23}$ are determined by the Yukawa couplings to the dominant right-handed tau. The mixing angle $\theta_{13}$ is then governed by the subdominant right-handed muon Yukawa couplings. Naturally small $\theta_{13}$ and sequential right-handed lepton dominance can be realized in type I see-saw models and their type II upgrades via spontaneously broken SO(3) flavour symmetry and real vacuum alignment. We discuss the prediction for $\theta_{13}$ in this scenario and corrections to it including the dependence on the neutrino mass scale.