Mei, JW (reprint author), CCAST, World Lab, POB 8730, Beijing 100080, Peoples R China.
A new ansatz of democratic lepton mixing is proposed at the GUT scale and the radiative corrections to its phenomenological consequences are calculated at the electroweak scale. We demonstrate that it is possible to obtain the experimentally favored results for both neutrino masses and lepton flavor mixing angles from this ansatz, provided the neutrino Yukawa coupling matrix takes a specific nontrivial pattern. The seesaw threshold effects play a significant role in the running of relevant physical quantities. (c) 2005 Elsevier B.V. All rights reserved.