CP violation in bipair neutrino mixing

There are experimentally determined two best-fit points for the atmospheric neutrino mixing angle θ23: sin2θ23=0.413 (case A) and sin2θ23=0.594 (case B). In the bipair neutrino mixing scheme, we predict sin2θ23=2−1 (case 1) to be consistent with the case A and sin2θ23=2−2 (case 2) to be consistent with the case B. If the case B is realized in nature, the bipair neutrino mixing provides a unique neutrino model consistent with the observation sin2θ23=0.594. However, the reactor neutrino mixing angle θ13 is predicted to be sin2θ13=0, which is inconsistent with the observation. We propose a new modification scheme to yield sin2θ13≠0 utilizing the charged lepton contribution and study its effect on both of CP-violating Dirac and Majorana phases, which is numerically estimated. It is found that there appear striking differences between the case 1 and the case 2 in their phase structure.