High scale mixing unification and large neutrino mixing angles

Abstract

Starting with the hypothesis that quark and lepton mixings are identical at or near the grand unified theory scale, we show that the large solar and atmospheric neutrino mixing angles together with the small reactor angle ${U}_{e3}$ can be understood purely as a result of renormalization group evolution provided the three neutrinos are quasidegenerate and have the same CP parity. The mechanism is found to work if the common Majorana mass for the neutrinos is larger than 0.1 eV, which falls right in the range reported recently and also in the range which will be probed in planned experiments.