Alignment of H(2p) following H+-He, Ar charge-changing collisions

Experimental results for the integral alignment A20 of H(2p) following charge-changing collisions of protons with helium and argon atoms are presented for incident energies of 1-5 keV and 35-300 keV. In addition, theoretical calculations in the continuum-distorted-wave approximation were performed. The observed discrepancies between experiment and theory are discussed.