The role of dynamic correlation in double ionization of He by high-energy protons and antiprotons

We present a convergent frozen-correlation approximation (CFCA) to evaluate multiple-ionization cross sections in ion-atom collisions. The theory allo ws the evaluation of total cross sections for double ionization without dyn amic correlation. We have studied double ionization of He by impact of high -energy protons and antiprotons. Our results for antiproton impact are in e xcellent agreement with experiment, thus proving the negligible role of dyn amic correlation. However, a discrepancy is obtained for proton impact, whi ch suggests that dynamic correlation may play a significant role in this ca se.