Simultaneous charge transfer and excitation

The amplitude for simultaneous electron transfer and excitation in an ion-atom collision is examined to first order in the electron-electron interaction. The amplitude is shown to separate into a sum of two parts, one corresponding to a resonant process (RTE) and the other to a non-resonant term (NTE). The NTE term, which assumes the motion of the two electrons to be uncorrelated in space and time, can be factored into the separate amplitudes for capture and excitation. Using a strong-potential Born wavefunction for the transferred electron, the two terms are seen to peak at different energies and with different widths. Possible interference effects of the two processes are discussed.