Strong correlations in the He ground state momentum wave function observedin the fully differential momentum distributions for the p plus He transfer ionization process

The four-particle process of proton-helium transfer ionization has been stu died using cold target recoil ion momentum spectroscopy to measure the mome nta of all three particles in the final state. Most of the electrons are em itted in the H-0 scattering plane and in the backward direction: The final state momentum distributions show discrete structures very different from t hose expected for uncorrelated capture and ionization. The measured momentu m pattern is interpreted to be due to a new transfer ionization reaction ch annel which results from strong correlations in the initial He ground state momentum wave function.