15min:

Y. LIU, J. LI, D. CHEN AND LI LI, Department of Physics and Center for Atomic and Molecular Sciences, Tsinghua University, Beijing 100084, China; R. W. FIELD, Department of Chemistry, MIT, Cambridge Mass 02139; AND A. M. LYYRA, Department of Physics, Temple University, Philadelphia PA 19122.

The Na₂ 3³_g and 4³_g⁺ states dissociate adiabatically to the 3s+4p atomic limit. Energy levels below the 3s+3d atomic limit of these two states have been observed by perturbation facilitated optical-optical double resonance (PFOODR) fluorescence excitation spectroscopy.^[^,^]. Energy levels above the 3s+3d atomic limit could not be observed by detecting molecular fluorescence but have been observed recently by detecting atomic 3d -> 3p fluorescence. The 3³_g and 4³_g⁺ states interact with the 3s+3d 2³_g and 3³_g⁺ states, respectively. As a result of the perturbation the 3³_g state strongly predissociates and the linewidth of levels close to the 3s+3d limit is about 15cm^-1. The 4³⁺_g state is weakly predissociated.