Extensive electron-nuclear angular momentum exchange in vibrational autoionization of np and nf Rydberg states of NO.

Vibrational autoionization of individual rotational levels of {ital np} ({nu}=1) and {ital nf} ({nu}=1) Rydberg states of nitric oxide (NO) with 11{le}{ital n}{le}15 have been studied employing two-color double-resonance excitation via the NO {ital A}{sup 2}{Sigma}{sup +} ({nu}{sub {ital i}}=1) state. The rotational state distributions of the resulting NO{sup +} {ital X}{sup 1}{Sigma}{sup +} ({nu}{sup +}=0) ion have been determined by time-of-flight photoelectron spectroscopy. These measurements show the occurrence of angular momentum exchange between the outgoing electron and the molecular-ion core, a process that has been commonly neglected in theoretical treatments of vibrational autoionization. {copyright} {ital 1996 The American Physical Society.}