Photogeneration of neutrinos and axions under the stimulating effect of a strong magnetic field

Photogeneration of neutrinos and axions at nuclei, gamma (Ze) --> gamma(nu< (<nu>)over bar>), gammaa, and inelastic photon-photon scattering, gamma gam ma --> gamma(nu<(<nu>)over bar>), gammaa, are considered in the 2D covarian t theory being developed for calculating matrix elements of Feynman diagram s in a strong magnetic field. Since the matrix elements of four-pole diagra ms are linear functions of the magnetic induction B, the contribution of th e radiative photogeneration of neutrinos at nuclei to the luminosity of mag netic neutron stars at early stages of their evolution may compete with URC A processes for values of B similar to (10(3)-10(4))B-0 (B-0 = m(e)(2)\e\ = 4.41 x 10(13) G). The upper estimate of the axion mass obtained from the c ondition of dominance of the neutrino luminosity over the axion luminosity for the proposed values of temperature and magnetic induction is in accord with other independent results. (C) 2001 MAIK "Nauka/Interperiodica".