Magnetic Feshbach resonances in Ba$^+$+Li collisions due to strong spin-orbit coupling
Abstract
We report a pronounced dependence of magnetic Feshbach resonance spectra on the initial hyperfine-Zeeman state of Li in ultracold Ba+Li collisions. The measured number and distribution of resonances differ significantly between the two lowest states despite their similar electron spin character. We address this puzzle by developing a comprehensive yet generic computational model calibrated against key statistical features in the experimental spectrum. We confirm that strong spin-orbit coupling induces essential changes in the distribution of resonances, leading to an increase in the number of resolvable resonances. Our model reproduces the statistics of the spectrum with the lowest Li state but struggles with the second-lowest state, where a significantly smaller number of resonances is experimentally observed.
Keywords
Cite
@article{arxiv.2507.12936,
title = {Magnetic Feshbach resonances in Ba$^+$+Li collisions due to strong spin-orbit coupling},
author = {Masato Morita and Joachim Siemund and Wei Wu and Daniel von Schoenfeld and Jonathan Grieshaber and Agata Wojciechowska and Krzysztof Jachymski and Thomas Walker and Fabian Thielemann and Tobias Schaetz and Michał Tomza},
journal= {arXiv preprint arXiv:2507.12936},
year = {2025}
}
Comments
7 pages, 9 figures and supplementary material (10 pages, 8 figures)