Feshbach Spectroscopy of a Shape Resonance

TL;DR

This paper introduces a novel spectroscopy method utilizing Feshbach resonances to investigate cold-collision properties, providing detailed measurements of shape resonance energy, lifetime, and wave interference patterns.

Contribution

The work presents a new technique combining Feshbach resonance association/dissociation with interference observations, advancing cold-collision spectroscopy methods.

Findings

Accurate measurement of shape resonance energy and lifetime.

Observation of interference between s and d waves.

Good agreement between experimental data and coupled-channels model.

Abstract

We present a new spectroscopy technique for studying cold-collision properties. The technique is based on the association and dissociation of ultracold molecules using a magnetically tunable Feshbach resonance. The energy and lifetime of a shape resonance are determined from a measurement of the dissociation rate. Additional spectroscopic information is obtained from the observation of a spatial interference pattern between an outgoing s wave and d wave. The experimental data agree well with the results from a new model, in which the dissociation process is connected to a scattering gedanken experiment, which is analyzed using a coupled-channels calculation.