Vibrationally elastic scattering of electrons by HCl

Abstract
Results of close-coupling calculations are reported, in which several models of the interaction potential are investigated. Cross sections for rotational transitions involving the lowest ten levels are obtained in the first detailed application of the MEAN approximation. The results are subject to a strong cooperative effect involving exchange and polarization. Rotationally elastic transitions are shown to be quite important at thermal energies and to dominate the total cross section above 4.0 eV. Transitions for which the angular momentum changes by two are found to be responsible for a broad resonance at ∼ 2.5 eV. No structure indicative of a resonance or virtual state at very low energies is, however, obtained. Total differential, momentum-transfer, and integrated cross sections are in satisfactory agreement with measured values.