Elastic scattering at high energy and fixed angle in QED

Summary

We show that the photon elastic-scattering amplitudes corresponding to irreducible diagrams scale as the energy approaches infinity with the scattering angle fixed. The lowest-order scaling functions are calculated. Existing experimental data on Delbrück scattering are in conflict with scaling, and we suggest that they be reanalysed or (and) additional experiments be done. We also show that, for photon scattering amplitudes, the violation of scaling is contained entirely in the dependence of the coupling constant on the momentum transfer.