Efimov states near a Feshbach resonance

TL;DR

This paper models three-body collisions near a Feshbach resonance, predicting atom-dimer interactions, recombination minima, and Efimov resonances, with results matching experiments in cesium and predictions for potassium.

Contribution

It introduces a detailed theoretical framework accounting for open and closed channel interactions, predicting Efimov states and recombination features near Feshbach resonances.

Findings

Predicted a sharp minimum in recombination losses at negative scattering length.

Achieved excellent agreement with cesium experimental data.

Predicted positions of Efimov resonances in potassium gas.

Abstract

We describe three-body collisions close to a Feshbach resonance by taking into account two-body scattering processes involving both the open and the closed channel. We extract the atom-dimer scattering length and the three-body recombination rate, predicting the existence at negative scattering length of a sharp minimum in the recombination losses due to the presence of a shallow bound level. We obtain very good agreement with the experimental results in atomic 133Cs of Kraemer et al. [Nature 440, 315 (2006)], and predict the position of Efimov resonances in a gas of 39K atoms.