Neutrino-photon scattering and its crossed processes in a background magnetic field

We study the neutrino-photon processes such as gamma gamma --> <v(v)over ba r>, v gamma --> v gamma, and <v(v)over bar> --> gamma gamma in a background magnetic field smaller than the critical magnetic field Bc + m(e)(2)/e. Us ing Schwinger's formalism, we extract leading magnetic-field contributions to the above processes. Our result is valid throughout the kinematic regime where both neutrino and photon energies are significantly smaller than m(w ). We briefly discuss the astrophysical implications of our result. (C) 199 9 Published by Elsevier Science B.V. All rights reserved.