Scattering properties of ground-state spin-polarized atomic hydrogen

Abstract

In this paper, the scattering properties of ground-state spin-polarized atomic hydrogen (H↓) are studied at 0K using the Lippmann–Schwinger formalism. The total, diffusion and viscosity cross sections, as well as the S-wave scattering length, are calculated. The S-wave scattering cross section is found to be the most significant partial wave contributing to the total cross section at low energy. The contribution of the higher angular momentum waves, especially the D-wave (ℓ=2), to the scattering increases with increasing relative momentum k. Our calculations are performed for three triplet-state potentials: Morse-type, Silvera and Born–Oppenheimer potentials. It is also noted that as k→0, the results of the Morse potential are larger than those of the Silvera and Born–Oppenheimer potentials. This is because of the exponential tail of the Morse potential which falls off more rapidly than the r−6 behavior of the Silvera and Born–Oppenheimer potentials. Also, the Morse potential is relatively shallower than the other two potentials. For high k, the Morse cross sections approach the corresponding Silvera cross sections. This is because these triplet-state potentials have almost the same short-range part. The total cross sections reflect the quantum oscillations arising from the diffraction caused by the repulsive short-range part of the potential. Our results are consistent with those obtained by other methods.