Effects of mass and electron exchange in H-H scattering

Abstract

The sensitive change of the singlet scattering length in H-H scattering was found using the Born-Oppenheimer (BO) model when the nuclear mass was replaced by the atomic mass. The mass effect influenced the BO potential immensely. In the close-coupling model, the main inputs to solve the integral equation are the scattering amplitudes for different transitions. The present investigation indicates that the effect of electron exchange in H-H scattering for all the transitions using the nuclear mass survives even in the asymptotic region whereas including the atomic mass this effect diminishes with the increase of energies. In other words, the exchange potential is ill conditioned when the nuclear mass is considered. This is the main reason for the significant change of the scattering length in H-H scattering.