https://doi.org/10.1140/epjp/s13360-025-06454-2
Regular Article
Centrality dependence of kinetic freeze-out parameters with fixed and variable flow profile in Au-Au collisions at 62.4 and 200 GeV
1
Hubei Key Laboratory of Energy Storage and Power Battery, School of Optoelectronic Engineering, School of New Energy, Hubei University of Automotive Technology, 442002, Shiyan, China
2
Department of Physics, Abdul Wali Khan University Mardan, 23200, Mardan, Pakistan
3
Department of Computer Sciences, Faculty of Computing and Information Technology, Northern Border University, 91911, Rafha, Saudi Arabia
4
Department of Physics, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, 11671, Riyadh, Saudi Arabia
5
College of Humanities and Sciences, Ajman University, P.O. Box 346, Ajman, UAE
a waqas_phy313@yahoo.com, 20220073@huat.edu.cn
b
ajaz@awkum.edu.pk
Received:
7
February
2025
Accepted:
19
May
2025
Published online:
10
June
2025
Using data from the STAR Collaboration at RHIC, we analyze the transverse momentum () spectra of the deuteron (d), anti-deuteron (
), and triton (t) generated in Au-Au collisions at center of mass energy (
)=62.4 and 200 GeV. We extract the mean transverse momentum (
), transverse flow velocity (
), and kinetic freeze-out temperature (
) for multiple centrality intervals using the blast wave model with Boltzmann–Gibbs statistics. According to our observations,
and
rise with collision energy, stating higher thermal energy at 200 GeV and stronger collective flow. Paradoxical variations can be seen in the centrality dependence of
: When
is fixed, it grows from central to peripheral collisions, implying a shorter fireball lifetime in peripheral collisions; when
is treated as a free parameter, it drops, which is consistent with a higher initial energy density in central collisions. Besides that, from central to peripheral collisions,
and
consistently decrease. Due to the improved coalescence efficiency, the
of d and
is larger at 200 GeV, whereas the
of t is larger at 62.4 GeV, suggesting less favorable conditions for t formation at higher energies. These findings show how collision energy, centrality, and particle mass interact complexly to determine collective behavior and freeze-out dynamics in heavy-ion collisions.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.