Observation of Strong Forward-Backward Asymmetries in Electron Emission from Overlapping Resonance States Produced by Transfer Excitation in 2.5-3.5-MeVC3++He Collisions

Autoionization-ejected electrons from the configuration $1s^{2}2pnl$ produced by transfer and excitation in 2.5-3.5-MeV ${\mathrm{C}}^{3+}$ +He collisions were measured. Several peaks produced by autoionization are seen to be strongly enhanced in the backward direction. At these peaks, it is found that two autoionizing states with opposite parities overlap within their natural widths (i.e., overlapping resonances). This results in a strong forward-backward asymmetry, which is explained by the fast decay of a polarized electron state.