Theory of High-Energy Diffraction Scattering. I

Recent theoretical results on high-energy scattering are extended. It is found that the form of the matrix elements in the high-energy limit can be readily understood in terms of energy denominators in pre-Feynman perturbation theory. On this basis, we give explicit rules to obtain the high-energy behavior of the sums of large classes of Feynman diagrams, for both the scattering of two extremely relativistic particles and that of one such particle by an external static potential. Application of these rules yields immediately all the previous results on high-energy elastic scattering, and also leads to a deeper understanding of exponentiation. These considerations suggest a simple and natural physical picture for high-energy elastic scattering and, by trivial extensions, also for diffraction and some inelastic scattering processes. We emphasize that this physical picture has the virtue of correctly yielding all the high-energy results of quantum electrodynamics.