Multielectron transitions resulting from interactions between target and projectile electrons in ionizing collisions

Interactions between target and projectile electrons leading to ionization of one of the collision partners and simultaneous excitation of the other are investigated for fast clothed-particle--clothed-particle collisions. For H-atom impact, the first Born approximation is used to demonstrate that the low-energy-electron emission is dominated by electron-electron rather than by electron-nucleus interaction processes. For a broad class of structured particle collision systems, the electron-electron interaction is shown to play an important, non-neglibible, role. Doubly differential cross sections for energetic H-He collisions illustrate this point