Vibrational excitation via high-energy shape resonances in molecules: v=0 to 1 excitation in CO

Abstract

The differential vibrational excitation cross section v=0 to v=1 has been obtained for CO in a crossed molecular-beam electron-beam apparatus in the 1-30 eV energy range. Besides the well known pi shape resonance at 1.8 eV, a broad and low-intensity peak centred at 19.5 eV is observed and attributed to a sigma shape resonance. Angular distributions within the sigma resonance energy show the contribution of the f wave (l=3).