ISSN - 10941622, Physical Review A - Atomic, Molecular, and Optical Physics, 2014, vol. 90, p. -
High-energy e+e- photoproduction in the field of a heavy atom accompanied by bremsstrahlung
© 2014 American Physical Society. Helicity amplitudes and the differential cross section of high-energy e+e- photoproduction accompanied by bremsstrahlung in the electric field of a heavy atom (i.e., the amplitudes of the process γ1Z→e+e-γ2Z) are derived. The results are exact in the nuclear charge number and are obtained in the leading quasiclassical approximation. They correspond to the leading high-energy small-angle asymptotics of the amplitude. It is shown that, in general, accounting for the Coulomb corrections essentially modify the differential cross section, which is different from the Born result. When the initial photon is circularly polarized, the Coulomb corrections lead to the asymmetry in the distribution over the azimuth angles φi of produced particles with respect to the replacement φi→-φi.