Eur. Phys. J. D (2016) 70: 153
https://doi.org/10.1140/epjd/e2016-70121-x

Regular Article

Alignment of H(2p) in collisions of protons and antiprotons with hydrogen atoms with screened Coulomb interaction

¹ Department of Physics, Faculty of Natural Sciences and Mathematics, Sts. Cyril and Methodius University, P.O. Box 162, 1000 Skopje, Macedonia
² Macedonian Academy of Sciences and Arts, P.O. Box 428, 1000 Skopje, Macedonia

^a e-mail: dragan.jakimovski@gmail.com

Received: 22 February 2016
Received in final form: 18 April 2016
Published online: 12 July 2016

Abstract

The effects of screened Coulomb interaction on the alignment of H(2p) state produced in collisions of hydrogen atoms with protons and antiprotons are investigated in the energy range 1–200 keV by using the two-center atomic orbital close-coupling (TC-AOCC) method. It is shown that the decrease of the binding energy of hydrogen nl-states and the reduction of the number of bound states with increasing the strength of the screening affect significantly the alignment degree and its energy dependence. In the case of antiproton-H collision the difference between the alignments with screened and unscreened Coulomb potential increases with increasing the strength of the screening in the entire energy range above 2 keV/u, while in the case of proton-H collision it does so only in the energy range 5–25 keV/u.