10min:

AMANDA ROSS, PATRICK CROZET, Université Lyon 1 and CNRS (LASIM, UMR 5579), 69622 Villeurbanne, France; HOUSSAM SALAMI, THOMAS BERGEMAN, Department of Physics and Astronomy, SUNY, Stony Brook, NY 11794-3800; OLIVIER DULIEU, Laboratoire Aimé Cotton, CNRS, Bât. 505, Campus d'Orsay, 91405 Orsay, France; CHRISTIAN LISDAT, Physikalisch-Technische Bundesanstalt, Braunschweig, Germany; BEDIHA BESER, JIANMEI BAI, A. MARJATTA LYYRA AND SVETLANA KOTOCHIGOVA, Department of Physics, Temple University, Philadelphia, PA 19122-6082.

The A ¹ _u⁺ and b ³ _0u states of the rubidium dimer has been re-investigated experimentally, adding to the considerable array of upper state term values determined from earlier work (performed at Laboratoire Aimé Cotton to characterize the electronic ground state). A polarization labelling experiment probed a series of levels from v=0, J=71 in the X ¹ _g⁺ state, and (A ¹ _u⁺ b ³ _0u) X ¹ _g⁺ fluorescence spectra have been recorded on an FT spectrometer following excitation of low-lying vibrational levels in the A state by a Ti:sapphire laser operating with long wavelength optics.

Data for ⁸⁵Rb₂, ⁸⁵Rb⁸⁷Rb and ⁸⁷Rb₂ are modeled using the discrete variable representation, fitting to numerical potential curves and Morse-type spin-orbit functions starting from ab initio potentials and spin-orbit functions. The fit has confirmed absolute vibrational numbering in the A state (the vibrational assignment in the b state looks convincing but is not definitive). The fit currently returns a root mean square residual of 0.075 cm^-1, which is 15 × the estimated experimental uncertainty, reflecting the fact that information particularly on the b state is still sparse. Including the b ³ ₁ component in the Hamiltonian did not improve the fit. Nevertheless, the fit provides useful estimates of term values and of spin-orbit mixing effects.\newline

Work at Stony Brook was supported by NSF grant PHY 0652459 and at Temple University by NSF PHY 0555608.