Nuclear-excited Feshbach resonances in electron attachment to molecular clusters

Using a high resolution (Delta E approximate to 1 meV) laser photoelectron attachment method, we have studied cluster anion formation in collisions of low energy electrons (1-180 meV) with N2O clusters. Both (N2O)(q)O- and (N 2O)(q)(-) ions are formed through a very sharp "zero energy resonance." Str ikingly narrow peaks (widths 2.3-4.4 meV) are observed in the (N2O)(q)O-) ( q greater than or equal to 5) ion yield just below the onsets for vibration al excitation of the N2O constituents. We interpret these peaks as nuclear- excited Feshbach resonances of temporary cluster anions (N2O)(N)(-) dissoci ating into (N2O)(q)O- (q < N). [S0031-9007(98)08086-7].