title: Precise determination of 6Li cold collision parameters by radio-frequency spectroscopy on weakly bound molecules.
abstract: We employ radio-frequency spectroscopy on weakly bound (6)Li(2) molecules to precisely determine the molecular binding energies and the energy splittings between molecular states for different magnetic fields. These measurements allow us to extract the interaction parameters of ultracold (6)Li atoms based on a multichannel quantum scattering model. We determine the singlet and triplet scattering lengths to be a(s) = 45.167(8)a(0) and a(t) = -2140(18)a(0) (1a(0) = 0.052 917 7 nm), and the positions of the broad Feshbach resonances in the energetically lowest three s-wave scattering channels to be 83.41(15), 69.04(5), and 81.12(10) mT.
authors.affiliation: Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Bartenstein
authors.forename: A
authors.initials: A
authors.lastname: Altmeyer
authors.forename: S
authors.initials: S
authors.lastname: Riedl
authors.forename: R
authors.initials: R
authors.lastname: Geursen
authors.forename: S
authors.initials: S
authors.lastname: Jochim
authors.forename: C
authors.initials: C
authors.lastname: Chin
authors.forename: J Hecker
authors.initials: JH
authors.lastname: Denschlag
authors.forename: R
authors.initials: R
authors.lastname: Grimm
authors.forename: A
authors.initials: A
authors.lastname: Simoni
authors.forename: E
authors.initials: E
authors.lastname: Tiesinga
authors.forename: C J
authors.initials: CJ
authors.lastname: Williams
authors.forename: P S
authors.initials: PS
authors.lastname: Julienne