Three- and four-body dynamics in single ionization of He by swift highly charged Au53+ ions

Doubly differential cross sections as a function of electron emission energy and transverse momentum transfer for single ionization of He by 3.6 MeV/u Au53+ ions are studied. The non-ionized electron dynamically screens the target nucleus. We analyse the effect of screening on the target and internuclear potentials. For this purpose we use different potentials with which we vary the interactions. This allows us to determine the mechanisms which are most important for different values of the dynamical variables.