Resonant atom-dimer collisions in cesium: Testing universality at positive scattering lengths

Year: 2014

Authors: Zenesini A., Huang B., Berninger M., Nagerl, H.-C., Ferlaino F., Grimm R.

Autors Affiliation: Univ Innsbruck, Inst Expt Phys, A-6020 Innsbruck, Austria; Univ Innsbruck, Zentrum Quantenphys, A-6020 Innsbruck, Austria; Leibniz Univ Hannover, Inst Quantum Opt, D-30167 Hannover, Germany; Austrian Acad Sci, Inst Quantenopt & Quanteninformat, A-6020 Innsbruck, Austria

Abstract: We study the collisional properties of an ultracold mixture of cesium atoms and dimers close to a Feshbach resonance near 550 G in the regime of positive s-wave scattering lengths. We observe an atom-dimer loss resonance that is related to Efimov’s scenario of trimer states. The resonance is found at a value of the scattering length that is different from a previous observation at low magnetic fields. This indicates nonuniversal behavior of the Efimov spectrum for positive scattering lengths. We compare our observations with predictions from effective field theory and with a recent model based on the van der Waals interaction. We present additional measurements on pure atomic samples in order to check for the presence of a resonant loss feature related to an avalanche effect, as suggested by observations in other atomic species. We could not confirm the presence of such a feature.


Volume: 90(2)      Pages from: 022704-1  to: 022704-8

DOI: 10.1103/PhysRevA.90.022704