Helicity amplitudes and differential cross section of high-energy e+e− photoproduction accompanied by bremsstrahlung in
the electric field of a heavy atom are derived. The results are exact in the nuclear charge number and 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, the Coulomb corrections essentially modify the differential cross section as compared to 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.
Ну вот, тянул-тянул любимый шеф с публикацией, и дотянулся до того, что люди сделали что-то близкое:((((