Analysis of structures in the cross sections for elastic scattering and spin exchange in low-energy H++H collisions -: art. no. 042711

Elastic scattering and spin exchange cross sections in H++H collisions are computed using accurate adiabatic potential curves for the center-of-mass energy range 10(-4) < E < 100 eV. Both cross sections show considerable structure which necessitates computation on a fine energy grid to resolve them. We analyze the structures using a comparison equation method to find the poles of the scattering matrix in the complex energy plane. We show that many features of the cross sections can be correlated with these poles and tabulate the positions of the most important poles. Finding stationary phases in the partial wave cross sections, we also explain in all details the glory oscillations of the elastic cross section that extends below 100 eV down to the lowest energies.