Renormalisation group analysis of single right-handed neutrino dominance

Abstract

We perform a renormalisation group (RG) analysis of neutrino masses and\nmixing angles in the see-saw mechanism in the minimal supersymmetric standard\nmodel with three right-handed neutrinos, including the effects of the heavy\nneutrino thresholds. We focus on the case that one of the right-handed\nneutrinos provides the dominant contribution to the 23 block of the light\nMajorana matrix, causing its determinant to approximately vanish and giving an\nautomatic neutrino mass hierarchy, so called single right-handed neutrino\ndominance which may arise from a U(1) family symmetry. In these models\nradiative corrections can increase atomospheric and solar neutrino mixing by up\nto about 10% and 5%, respectively, and may help to achieve bi-maximal mixing.\nSignificantly we find that the radiative corrections over the heavy neutrino\nthreshold region are at least as important as those usually considered from the\nlightest right-handed neutrino down to low energies.\n