Coulomb Corrections to Delbrück ScatteringONLINE ONLY

Delbrück scattering is the process in which a photon is elastically scattered by the Coulomb field of an atomic nucleus via the production of a virtual electron-positron pair. It is one of the few non-linear quantum electrodynamical processes that can be observed experimentally and, hence, testing the respective theoretical predictions serves as an important check for the standard model. Despite the strong motivation, most theoretical studies in the past have been limited to the first-order Born approximation in which all interactions with the nucleus beyond the lowest order are neglected. This assumption makes the predictions unreliable in the high-Z regime. Therefore, we present a new approach to evaluate  Delbrück amplitudes without any approximation regarding the coupling to the nucleus.