Efimov resonances in atom-diatom scattering

Abstract

We have investigated three identical bosons with very large pairwise scattering lengths. Normally such a situation is associated with Efimov states, where the three-body system has a set of very loosely bound states close to the three-body threshold. In the limit of infinite scattering length, the three-body system has infinitely many bound states. If, however, the two-body subsystems have deep lying two-body bound states, the Efimov states lie over the corresponding thresholds for breakup. We have calculated the positions and widths of these Feshbach resonances for some simple potentials numerically and have extracted the systematics. We explore the possibility of observing such Efimov resonances in atom-diatom scattering experiments with alkali atoms.