ELECTRON-POSITRON PAIR PRODUCTION BY A NEUTRINO IN AN EXTERNAL ELECTROMAGNETIC-FIELD

The fourth order radiation correction to the Dirac neutrino mass in an external electromagnetic field is considered. The imaginary part of this correction corresponds to production of electron-positron pairs by a neutrino. The rate of this process is obtained for the cases of weak and strong magnetic fields, and for very high energies, where the propagator of the charged vector boson is essential. For conditions existing on the surface of a neutron star the rate of pair production in a strong magnetic field is shown to be 10 times greater than the corresponding value obtained for the case of metallic iron, the radiation length being 0.01 of a typical neutron star radius.