Breakdown of the spectator concept in low-electron-energy resonant decay processes.

We suggest that low energy electrons, released by resonant decay processes, experience substantial scattering on the electron density of excited electrons, which remain a spectator during the decay. As a result, the angular emission distribution is altered significantly. This effect is expected to be a common feature of low energy secondary electron emission. In this letter, we exemplify our idea by examining the spectator resonant interatomic Coulombic decay (sRICD) of Ne dimers. Our theoretical predictions are confirmed by a corresponding coincidence experiment.