On the description of electronic final states in K-shell ionization by protons

The choice of free electronic wavefunctions in the description of K-shell ionization by protons is discussed. The previously known discrepancies between PWBA and SCA results are shown to be entirely due to two different choices of electronic wavefunctions. Calculations in the SCA framework with Hartree-Fock-Slater wavefunctions are reported. Some general features of the SCA calculations are discussed.