Abstract
Considering the symmetry, we discuss a direct linkage between phases of flavor neutrino masses and leptonic violation by determining three eigenvectors associated with for a complex flavor neutrino mass matrix in the flavor basis. Since the Dirac violation is absent in the symmetric limit, leptonic violation is sensitive to the symmetry breaking, whose effect can be evaluated by perturbation. It is found that the Dirac phase () arises from the symmetry breaking part of and an additional phase () is associated with the symmetric part of , where stands for an matrix element (). The phase is redundant and can be removed but leaves its effect in the Dirac violation characterized by . The perturbative results suggest the exact formula of mixing parameters including that of and , which turns out to be free from the effects of the redundant phases. As a result, it is generally shown that the maximal atmospheric neutrino mixing necessarily accompanies either or , the latter of which indicates maximal violation, where is the mixing angle.
- Received 9 December 2006
DOI:https://doi.org/10.1103/PhysRevD.75.055001
©2007 American Physical Society