Zeeman quantum-beat spectroscopy of NO2:: Eigenstate-resolved Lande gF factors near dissociation threshold

The sign and magnitude of Lande g(F) factors for single NO2 rovibronic (J=3/2) eigenstates in the 15 cm(-1) region below dissociation threshold (D-0=25 128.57 cm(-1)) were investigated using Zeeman quantum-beat spectroscopy. The derived Lande g(F) factors exhibit pronounced fluctuations about an average much smaller than expected in the absence of rovibronic perturbations, which destroy the goodness of the N and K quantum numbers and the J=N+S coupling scheme. The F=J+I coupling scheme was found to be valid near D-0 to within the uncertainty of our measurements, and the average Lande g(F) factors near dissociation threshold are in good agreement with those calculated under the assumption of complete rovibronic mixing. Our findings do not provide evidence for the participation of repulsive quartet states near dissociation threshold. (C) 2002 American Institute of Physics.