Techniques the authors developed to include correlation in the double-excitation of atoms are applied to a second two-electron process, excitation–ionization by proton versus antiproton impact. The second-order cross section, in the closure approximation and using pseudostates for the unbound electron, reproduces only a small percentage of the experimental factor of 2 difference for positively versus negatively charged projectiles. Inclusion of a portion of the third-order term yields a significant contribution near 0.5 MeV.
Third-Order Pseudostate Calculation Of Excitation-Ionization Of Helium By Protons And AntiprotonsCanadian Journal of Physics
Locate the Documenthttps://doi.org/10.1139/p96-081
Citation InformationStraton, J. C., Wang, J., McGuire, J. H., & Nagy, L. (1996). Third-order pseudostate calculation of excitation–ionization by protons and antiprotons. Canadian journal of physics, 74(7-8), 554-558.