Abstract
We present a combined experimental and theoretical study of the spectrum of magnetically tunable Feshbach resonances in NaLi Na collisions. In the accompanying paper, J. J. Park, H. Son, Y.-K. Lu, T. Karman, M. Gronowski, M. Tomza, A. O. Jamison, and W. Ketterle, Phys. Rev. X 13, 031018 (2023), we observe experimentally 8 and 17 resonances occurring between and 1400 G in upper and lower spin-stretched states, respectively. Here, we perform ab initio calculations of the NaLi Na interaction potential and describe in detail the coupled-channel scattering calculations of the Feshbach resonance spectrum. The positions of the resonances cannot be predicted with realistic uncertainty in the state-of-the-art ab initio potential, but our calculations yield a typical number of resonances that is in near-quantitative agreement with experiment. We show that the main coupling mechanism results from spin-rotation and spin-spin couplings in combination with the anisotropic atom-molecule interaction. The calculations furthermore explain the qualitative difference between the numbers of resonances in either spin state.
7 More- Received 20 March 2023
- Accepted 8 June 2023
DOI:https://doi.org/10.1103/PhysRevA.108.023309
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