Improved semiclassical Regge-pole description of rainbow scattering

Abstract

A phase-integral formula for calculating Regge-pole residues, which has recently been derived by Fr\"oman and Fr\"oman [preceding paper, Phys. Rev. A 43, 3563 (1991)], promises to be a powerful tool in the complex angular-momentum description of scattering. The present authors demonstrate the power, simplicity, and usefulness of that formula already in the first-order approximation. Application to proton-neon elastic scattering reveals that the new residue formula considerably improves the existing semiclassical Regge-pole description of the prominent rainbow oscillations in the differential cross section.