Full Numerical Estimation of Neutrino Mixing Parameters from Solar Neutrino Data

We have numerically computed survival probabilities of solar neutrinos interacting with matter via MSW mechanism in the full three generation formalism with ∆m23 = 2.2 × 10−3 eV. For θ13 ∼ 30◦, we confirm the two regions found in the two generation case, (1) with the most likelyhood, small sin(2θ12) ∼ 0.006, (2) with less likelyhood, large sin(2θ12) ∼ 0.5. For θ13 ∼ 30◦, we find an additional region, (3) with even less likelyhood, 10−5 < ∆m12 < 10 −4 eV and/or 10−4 < sin(2θ12) < 0.5. Assuming that the case (1) is valid, we predict that θ13 ' 15◦.