Angular distribution of Auger electrons emitted through the resonant transfer and excitation process following O^{5+}+He collisions

This Letter reports the first measurements of the angular distribution of Auger electrons emitted from the decay of the (1s2s2${\mathit{p}}^2$ ${)}^3$D ${\mathrm{O}}^{4+\mathrm{*}\mathrm{*}}$ doubly excited state formed predominantly through resonant transfer and excitation (RTE) in collisions of 13-MeV ${\mathrm{O}}^{5+}$ projectiles with He. The (1s2s2${\mathit{p}}^2$ ${)}^3$D angular distribution is strongly peaked along the beam direction, in agreement with recent calculations of the RTE angle-dependent impulse approximation. Furthermore, interference effects between the RTE and the elastic target direct-ionization channels are observed.