Ionizations in Ps-atom scattering

Abstract

Ionizations in Ps-atom scattering are studied using three different types of target: H, He and Li. Three different types of ionization cross-sections are compared, considering a large number of excitation channels of both the atoms in each system. The findings in Ps-Li system is much different from Ps-H and Ps-He. The target-ionization and both ionization are competeting with each other in Ps-H and Ps-He systems; whereas in Ps-Li, both ionizations are negligible and target-ionization is competeting with Ps-ionization. However, Ps-ionization is important in all the three systems. The slow rate of falling of the total ionization cross-sections with the increase of energy, indicates the importance of ionization at all the energies above thresholds. Comparison of the total ionization cross-section curves of the three different systems indicates the importance of the forces due to mutual polarization in Ps-atom scattering through shifting of ionization peaks.