Quantum electrodynamics processes in the interaction of high-energy particles with atoms

The recently developed method of quasiclassical Green's functions of the Dirac equation in the variously configured external fields has provided breakthrough insight into fundamental quantum electrodynamics processes whereby high-energy particles interact with atoms. This paper reviews latest calculated results, exact in the atomic field parameters, on the cross sections for electron–positron high-energy photoproduction, the single bremsstrahlung cross section for relativistic electrons and muons in an atomic field, double bremsstrahlung cross sections, etc. In many cases, the calculations are performed in the quasiclassical approximation with the inclusion of the first-order quasiclassical correction.