Inverse beta-decay of arbitrarily polarized neutrons in a magnetic field

摘要

We calculate the cross section of the inverse beta decay process, $\nu_e+n\top+e$, in a background magnetic field which is much smaller than $m_p^2/e$.Using exact solutions of the Dirac equation in a constant magnetic field, wefind the cross section for arbitrary polarization of the initial neutrons. Thecross section depends on the direction of the incident neutrino even when theinitial neutron is assumed to be at rest and has no net polarization. Possibleimplications of the result are discussed.