Roy Glauber and Asymptotic Diffraction Theory

TL;DR

This paper reviews Glauber's asymptotic diffraction theory, explaining how interference of semiclassical amplitudes describes elastic scattering and how stationary points influence diffraction patterns at high momentum transfers.

Contribution

It provides a comprehensive overview of Glauber's asymptotic diffraction theory, emphasizing the role of complex stationary points in scattering phenomena.

Findings

Stationary points are located at complex impact parameters.

Interference between semiclassical amplitudes explains diffraction patterns.

Stationary points approach singularities at large momentum transfers.

Abstract

This is a review of Glauber's asymptotic diffraction theory, in which diffractive scattering is described in terms of interference between semiclassical amplitudes, resulting from a stationary-phase approximation. Typically two such amplitudes are sufficient to accurately describe elastic scattering, but the stationary points are located at complex values of the impact parameter. Their separation controls the interference pattern, and their offsets from the real axis determine the overall fall-off with momentum transfer. Asymptotically, at large momentum transfers, the stationary points move towards singularities of the profile function. I also include some reminiscences from our collaboration.