Feshbach Resonances in Cold Collisions: Benchmarking State of the Art ab initio Potential Energy Surfaces

TL;DR

This paper evaluates the effectiveness of cold collision measurements in validating and distinguishing high-quality potential energy surfaces for the Ne-H$_2^+$ system, emphasizing the importance of resonance resolution.

Contribution

It demonstrates that cold collision experiments can effectively validate and differentiate state-of-the-art PESs, especially with improved energy resolution to resolve Feshbach resonances.

Findings

Final state distributions can identify accurate PESs.

Enhanced energy resolution enables resonance resolution.

Cold collision data can validate PES accuracy.

Abstract

High-quality potential energy surfaces (PES) are a prerequisite for quantitative atomistic simulations, with both quantum and classical dynamics approaches. The ultimate test for the validity of a PES are comparisons with judiciously chosen experimental observables. Here we ask whether cold collision measurements are sufficiently informative to validate and distinguish between high-level, state-of-the art PESs for the strongly interacting Ne-H$_2^+$ system. We show that measurement of the final state distributions for a process that involves only several metastable intermediate states is sufficient to identify the PES that captures the long-range interactions properly. Furthermore, we show that a modest increase in the experimental energy resolution will allow for resolving individual Feshbach resonances and enable a quantitative probe of the interactions at short and intermediate range.