CCAST, World Lab, Beijing 100080, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
We argue that the tri-bimaximal neutrino mixing pattern V-0 or its generalized form V-0('), which includes two arbitrary Majorana phases of CP violation, may result from an underlying flavor symmetry at a superhigh energy scale close to the seesaw scale (similar to 10(14) GeV). Taking the working assumption that three neutrino masses are nearly degenerate, we calculate radiative corrections to V-0 and V-0(') in their evolution down to the electroweak scale (similar to 10(2) GeV). Three mixing angles of V-0 or V-0(') are essentially stable against radiative corrections in the standard model (SM). In the minimal supersymmetric standard model (MSSM), however, V-0 is in general disfavored and V-0(') can be compatible with current neutrino oscillation data if its two Majorana phases alpha(1) and alpha(2) are properly fine-tuned. We also find that it is possible to radiatively generate the CP-violating phase delta from alpha(1) and alpha(2), and delta may keep on staying at its quasi-fixed point in either the SM or the MSSM. (c) 2005 Elsevier B.V. All rights reserved.