Dissociation of Feshbach Molecules into Different Partial Waves

TL;DR

This paper presents a theoretical model explaining how ultracold Feshbach molecules dissociate into multiple partial waves, linking the process to multichannel scattering resonances and enabling predictions of decay rates, branching ratios, and phase relations.

Contribution

It introduces a detailed theoretical framework connecting molecular dissociation into partial waves with multichannel scattering theory, applicable to recent experimental observations.

Findings

Decay rate and branching ratios can be predicted or experimentally determined.

The model explains the phase relationships between outgoing partial waves.

Application to 87Rb demonstrates the model's relevance to real experiments.

Abstract

Ultracold molecules can be associated from ultracold atoms by ramping the magnetic field through a Feshbach resonance. A reverse ramp dissociates the molecules. Under suitable conditions, more than one outgoing partial wave can be populated. A theoretical model for this process is discussed here in detail. The model reveals the connection between the dissociation and the theory of multichannel scattering resonances. In particular, the decay rate, the branching ratio, and the relative phase between the partial waves can be predicted from theory or extracted from experiment. The results are applicable to our recent experiment in 87Rb, which has a d-wave shape resonance.