A distorted-wave study of electronic excitation to some low-lying states of CO by electron impact

The distorted-wave approximation is applied to study electron-impact excitation leading to the a (II)-I-3, b (3) Sigma(+), A (II)-I-1 and B (1) Sigma(+) states of CO in the 20-100 eV range. Our calculated DCS and ICS are compared with available theoretical and experimental data. In general our cross sections are in quite good agreement with previous two- and five-state Schwinger multichannel results. Also, good qualitative agreement with the experimental data is obtained. However, in general our theory overestimates the cross sections. In comparison with a previous DWA study, our work reveals the strong influence of the description of the target wavefunctions on the calculated cross sections.