When diffraction rules the stereodynamics of rotationally inelastic collisions

TL;DR

This paper demonstrates that diffraction of matter waves from a two-dimensional potential core governs the stereodynamics of rotationally inelastic collisions, with a model accurately matching detailed calculations across various systems.

Contribution

It introduces a diffraction-based model that captures the stereodynamics of atom-molecule collisions, validated against close-coupling calculations for multiple systems.

Findings

Model results agree with exact calculations across channels and energies.

Diffraction patterns serve as fingerprints for stereodynamics.

Stereodynamics are primarily governed by matter wave diffraction.

Abstract

Following upon our recent work on vector correlations in the Ar-NO collisions [PCCP 12, 1038 (2010)], we compare model results with close-coupling calculations for a range of channels and collision energies for the He-NO system. The striking agreement between the model and exact polarization moments indicates that the stereodynamics of rotationally inelastic atom-molecule collisions at thermal energies is governed by diffraction of matter waves from a two-dimensional repulsive core of the atom-molecule potential. Furthermore, the model polarization moments characterizing the He-NO, He-O$_2$, He-OH, and He-CaH stereodynamics are found to coalesce into a single, distinctive pattern, which can serve as a "fingerprint" to identify diffraction-driven stereodynamics in future work.