Low-temperature scattering with the R-matrix method: from nuclear scattering to atom-atom scattering and beyond

TL;DR

This paper introduces RmatReact, a novel R-matrix computational method tailored for ultracold atom-atom scattering, demonstrating its effectiveness through numerical comparisons and resonance analysis, and paving the way for simulating complex polyatomic reactions.

Contribution

The paper presents a new R-matrix method, RmatReact, specifically designed for ultracold atom-atom scattering, extending the applicability of quantum scattering simulations.

Findings

Numerical comparisons show RmatReact's accuracy against established methods.

Resonance analysis in ultracold argon atom scattering.

Foundation for future polyatom-polyatom reactive collision simulations.

Abstract

The R-matrix method is a fully-quantum time-independent scattering method, used to simulate nuclear, electron-atom, electron-ion, electron-molecule scattering and more. Here, a novel R-matrix method, RmatReact, is presented as applied to ultracold (sub-Kelvin) atom-atom scattering. This is in response to experimental methods which in recent decades have facilitated the routine use of ultracold atoms and small molecules in experiments. This project lays the groundwork for future codes to eventually simulate polyatom-polyatom reactive collisions. Results are presented in this paper for numerical comparisons to other established methods, and for resonances in the elastic scattering of ultracold argon atoms.