Quantum phenomena that lead to the formation of long-lived collision complexes, such as scattering resonances play a central role in cold molecular collisions. These resonances are fundamental probes of the fine details of internuclear interactions and serve as a benchmark for current computational methods.
Here we present a joint experimental and theoretical study where we are able to generate and investigate the multi-channel decay of a Feshbach resonance state with quantum state-to-state resolution. Our method is based on the coincidence detection of electron/ion momenta in Penning ionization collisions between metastable noble gas atoms and neutral molecules. Here, in a single measurement, we obtain both the energy and the composition at the continuum of each resonance state. Such a tomography of the Feshbach resonance states provides several tens of quantum numbers per measurement. We show that our results deviate from a purely statistical approach where the probability to decay into each open channel scales as its degeneracy level.
We also present an experimental scheme for control of tomography of the Feshbach states which is based on the initial constraint of total angular momentum at the Ionization step of the dynamics. The latter is motivated by our recent observation of a partial wave resonance at the lowest state of relative angular momentum.
|Presenter name||Baruch Margulis|