Ionization of Atoms by Antiproton Impact

The theory of the ionization of atoms by antiproton impact is superficially similar to that for ionization by electron impact, indeed one of the possible time reversed processes is the ionization of protonium by electron impact. The large mass of the antiproton relative to the electron introduces key differences which have emerged in quantitative calculations. We have employed the advanced adiabatic approximation to compute ionization and protonium formation. Results are compared with classical trajectory Monte Carlo calculations.