Studies on ionization and excitation processes in Ps-Li scattering

Three different types of ionization and excitation processes are studied in detail for the scattering of positronium (Ps) by the simplest alkali atom (Li) using a Coulomb-Born approximation for ionization and first-Born approximation for excitation. This is the first work where orthogonalized Coulomb wave is used to represent the ionized electron for Ps-Li scattering using a single-electron and a three-electron prescription of the target. Li is chosen to minimize the effect of intrinsic correlation among the target atomic electrons so that it can extract the basic physics more accurately. All the possible Coulomb interactions are considered exactly. Comparative studies of different cross-sections using two different representations of the target provide us the informations to enrich our ideas about the system and the important role of core electrons.