Abstract
We study collisional heating in a cold mixture near a broad Feshbach resonance at 661 G. At the high field slope of the resonance, we find an enhanced three-body recombination rate that we interpret as a heteronuclear Efimov resonance. With improved Feshbach spectroscopy of two further resonances, a model for the molecular potentials has been developed that now consistently explains all known Feshbach resonances of the various Li-Rb isotope mixtures. The model is used to determine the scattering length of the observed Efimov state. Its value of Bohr radii supports the currently discussed assumption of universality of the three-body parameter also in heteronuclear mixtures.
- Received 11 November 2014
DOI:https://doi.org/10.1103/PhysRevLett.115.043201
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