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  • Open Access

Effect of event classification on the Tsallis thermometer

László Gyulai1, Gábor Bíró1,2, Róbert Vértesi1,*, and Gergely Gábor Barnaföldi1

  • 1HUN-REN Wigner Research Centre for Physics, 29–33 Konkoly–Thege Miklós Str., H-1121 Budapest, Hungary
  • 2ELTE Eötvös Loránd University, Institute of Physics, 1/A Pázmány Péter Sétány, H-1117 Budapest, Hungary

  • *Contact author: vertesi.robert@wigner.hun-ren.hu
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Phys. Rev. D 113, 016021 – Published 26 January, 2026

DOI: https://doi.org/10.1103/x93k-88t7

Abstract

We analyze identified hadron spectra in pp collisions at s=13  TeV measured by ALICE within a nonextensive statistical framework. Spectra classified by multiplicity, flattenicity, and spherocity were fitted with the Tsallis-Pareto distribution, and the parameters were studied on the Tsallis thermometer. Multiplicity and flattenicity classes follow a previously observed scaling, while the nonextensivity parameter shows a distinct sensitivity to the spherocity. A data-driven parametrization confirms a proportionality between the Tsallis temperature and mean transverse momentum, offering a simple estimate of the effective temperature. These results highlight the ability of the Tsallis thermometer to capture both multiplicity and event-shape effects, linking soft and hard processes in small systems.

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Phys. Rev. D 113, 016021– Published 26 January, 2026
  • Received 7 October 2025
  • Accepted 5 January 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. Funded by SCOAP3.

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