Vibrationally resolved capture cross section in p + H 2 collision

The electron-capture process p + H 2 → H ( 1 s ) + H 2 + ( 1 s σ ) is described using distorted-wave-Born models by considering the influence of the vibrational motions of H 2 and H 2 + within the framework of the Born–Oppenheimer approximation. Non-dissociative and dissociative capture cross sections are calculated for incident proton energies E C = 20–300 keV. The vibrational distribution of H 2 + ( 1 s σ ) is compared with that of the Franck–Condon factor. They are in fairly good agreement for E C < 100 keV, and discrepancies arise for higher E C .