Full electron description of antiproton collisions with neon and argon atoms in the keV energy range

We investigate keV collisions between antiprotons and the rare-gas atoms neon and argon. We use a correlated approach in which the eight electrons from the L shell of neon and M shell of argon are active and up to two-electron processes are included, going thus beyond the approximate theoretical approaches used so far. Our results show that the electronic correlation plays a major role in the single- and double-ionization processes. Furthermore, we show that two-electron processes contribute significantly to the electronic stopping power. These results apply to both target atoms studied in this paper and we therefore conclude that a correlated approach is in general necessary to obtain accurate antiproton electronic stopping-power cross sections. Our paper paves the way to a better understanding and knowledge of antiproton collision physics.