A modified approach to Glauber approximation for particle-atom collisions

Abstract

In the present approach a multi-angular-momentum expansion of each order of the exact scattering amplitude is developed. Introducing the usual high energy, small angle approximation, but retaining a finite value for the mean excitation energy of the atom in its intermediate states, one obtains a new expression for the amplitude. It resembles the Glauber amplitude in character, but most of the well known shortcomings of the conventional Glauber amplitude are absent. It is also indicated how to include higher order terms in the phase function of the S -matrix.