Rotational inelasticity in He-HF collisions: A computational analysis

ntegral and differential cross sections are computed for the He-HF system by using an interaction potential recently reported in the literature. Rigorous close-coupling (CC) equations are solved at the collision energies which were very recently tested in molecular beam experiments involving the above partners and the general behaviour of the integral, state-to-state excitation cross sections is here studied over a wide range of thermal energies. Calculations confirm the general experimental findings of unusually small rotational inelasticity for the present system, while the validity of impulsive dynamical approximations for the involved energy transfers is also critically analysed and found to be only qualitatively correct for a target molecule with the wide rotational level spacings and relatively short-range anisotropic couplings as those shown by HF