15min:

M. A. BELLOS, R. CAROLLO, D. RAHMLOW, J. BANERJEE, M. BERMUDEZ, E. E. EYLER, P. L. GOULD AND W. C. STWALLEY, Department of Physics, University of Connecticut, Storrs, CT 06269.

We report photoassociation of ultracold atoms to vibrational levels blue of the ⁸⁵Rb₂ 5s+ 5p_1/2 asymptote, in the previously-unobserved 2 (0_g⁺) Hund's case (c) state that corresponds to the 2 ¹ _g⁺ state in Hund's case (a). These excited-state ultracold molecules decay to the a ³ _u⁺ state and are detected by pulsed REMPI through the 2 ³ _g⁺ state. We also see an order of magnitude enhancement in the v' = 111, J' = 5 ro-vibrational level of the 2 (0_g⁺) state and present evidence for resonant coupling between this level and the v' = 155 of the 2 (1_g) state, seen earlier in photoassociative trap loss. Following photoassociation to the observed levels of the 2 (0_g⁺) state, spontaneous decay populates vibrational levels approximately halfway up the a ³ _u⁺ potential well, including levels v'' = 18 though v'' = 24. This pathway complements the blue-detuned photoassociation technique previously developed by this group, which accesses the bottom of the a state potential. This work is supported by the NSF and AFOSR.