On laser−induced charge transfer in the HeH2+ quasimolecule

In a recent publication, the charge transfer cross section for He2++H(ls) collisions through photon-assisted 2pσ–3dσ transitions was calculated; this calculation, however, contained several errors whose quantitative–even qualitative effect on the results is not obvious. We present a correct evaluation of this laser-induced cross section, which turns out to be larger, and present a maximum for longer wavelengths, than the values previously reported. In addition, we have checked the applicability of perturbation theory, of the stationary phase, uniform and Landau–Zener approximations, and the importance of potentially competitive photon-assisted reactions.