摘要
Ionization-detected absorption spectra of autoionization Rydberg states converging to the (010) vibrational level of HCO PLU was reported. Sharp second-photon resonances were observed in transitions from first-photon-prepared transition states. The spectra was compared in order to characterize observed resonances in terms of good angular momentum quantum number, N. The convergence of series to detailed cation-ore rotational quantum numbers, N + was established by Rydberg analysis.