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Cold Atomic Collisions Studied by Molecular Spectroscopy



C Samuelis, Eite Tiesinga, T Laue, M Elbs, H Knockel, E Tiemann


We observe bound states just below the dissociation limit and shape and Feshback resonances between the ground state hyperfine asymtotes by Raman spectroscopy on a molecular beam of sodium dimers. The rotational selectivity of a two-photon transition gives access to specific states of nuclear motion and thus to cold collision properties of two colliding atoms. Modeling of the collisional resonance structures requires a multichannel treatment of the nuclear dynamics that uses highly accurate X1ς+g and a 3ς+u potentials. These potentials are constructed from newly measured bound levels just below the ground state asymptote and bound state information available in the literature. We also present simulations of the spectrum between the ground state hyperfine asymptotes. The good agreement shows that accurate potentials obtained from bound state information are able to reproduce scattering properties of two colliding sodium atoms. From this analysis we find for the scattering lengths a(f=2)=a1,-1 = 52.98(40) ao, a singlet = 19.20(30) ao and a triplet = 19.20(30) ao and 1 triplet = 62.51(50) ao where 1 ao = 0.0529177 nm.
Physical Review A (Atomic, Molecular and Optical Physics)
No. 1


hyperfine structure, Raman spectroscopy, sodium, ultra-cold collisions


Samuelis, C. , Tiesinga, E. , Laue, T. , Elbs, M. , Knockel, H. and Tiemann, E. (2001), Cold Atomic Collisions Studied by Molecular Spectroscopy, Physical Review A (Atomic, Molecular and Optical Physics) (Accessed June 18, 2024)


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Created December 31, 2000, Updated October 12, 2021