Nonadiabatic level crossing in resonant neutrino oscillations

Analytic results are presented for the probability of detecting an electron neutrino after passage through a resonant oscillation region. If the electron neutrino is produced far above the resonance density, this probability is simply given by

//sub e//sub =/>≅sin2theta0 +P/sub x/cos2theta0, where theta0 is the vacuum mixing angle. The probability is averaged over the production as well as the detection positions of the neutrino and P/sub x/ is the Landau-Zener transition probability between adiabatic states. Finally, this result is applied to resonance oscillations within the solar interior