Current neutrino oscillation data indicate that the 3x3 lepton flavor mixing matrix V is likely to be symmetric about its V_{ e3}-V_{ \mu 2}-V_{ \tau 1} axis. This off-diagonal symmetry corresponds to three pairs of { \it congruent} unitarity triangles in the complex plane. Terrestrial matter effects can substantially modify the genuine CP-violating parameter and off-diagonal asymmetries of V in realistic long-baseline experiments of neutrino oscillations.
Categories: hep-ph hep-ex