Inverse beta-decay in magnetic fields

We calculate the cross section of the inverse beta decay process, $\nu_e+n\to p+e$, in a magnetic field which is much smaller than $m_p^2/e$. Using exact solutions of the Dirac equation in a constant magnetic field, we find that the cross section depends on the direction of the incident neutrino even when the initial neutron is assumed to be at rest. We discuss the implication of this result for pulsar kicks.