Coupled-channel integral-equation approach to antiproton–hydrogen collisions

Abstract

A fully quantal integral-equation approach to ion–atom collisions is developed along the lines of the convergent close-coupling approach to electron–atom scattering. The approach starts from the exact three-body Schrödinger equation for the scattering wavefunction and leads to coupled-channel Lippmann–Schwinger equations for the transition amplitudes in the impact-parameter representation, with the relative motion of the heavy particles treated quantum mechanically. The method is applied to calculate antiproton collisions with atomic hydrogen. Integrated total, excitation and ionization cross sections are calculated in the energy range from 1 keV to 1 MeV.