Quasiclassical Green function and Delbruck scattering in a screened Coulomb field

TL;DR

This paper derives a simple integral representation for the quasiclassical Green function of the Dirac equation in spherical fields and applies it to calculate Delbruck scattering amplitudes in screened Coulomb potentials.

Contribution

It introduces a new integral form for the Green function in spherical fields, enabling improved calculations of scattering amplitudes in quantum electrodynamics.

Findings

Green function integral representation derived

Application to Delbruck scattering amplitudes

Enhanced understanding of scattering in screened Coulomb fields

Abstract

A simple integral representation is derived for the quasiclassical Green function of the Dirac equation in an arbitrary spherically-symmetric decreasing external field. The consideration is based on the use of the quasiclassical radial wave functions with the main contribution of large angular momenta taken into account. The Green function obtained is applied to the calculation of the Delbruck scattering amplitudes in a screened Coulomb field.