https://doi.org/10.1140/epjc/s10052-025-14049-5
Regular Article - Experimental Physics
Investigating late-stage particle production in pp collisions with balance functions
1
Faculty of Physics, University of Bucharest, 077125, Magurele, Romania
2
Institute of Space Science–INFLPR Subsidiary, 077125, Magurele, Romania
3
Department of Physics and Astronomy, Wayne State University, 48201, Detroit, USA
4
Division of Particle and Nuclear Physics, Department of Physics, Lund University, Box 118, 221 00, Lund, Sweden
5
International Center for High Energy Physics and Applications, Lovely Professional University, 144411, Punjab, India
Received:
21
November
2024
Accepted:
8
March
2025
Published online:
20
March
2025
Balance functions have been regarded in the past as a method of investigating the late-stage hadronization found in the presence of a strongly-coupled medium. They are also used to constrain mechanisms of particle production in large and small collision systems. Charge balance functions for inclusive and identified particle pairs are reported as a function of charged particle multiplicity in proton–proton collisions simulated with the PYTHIA8 and the EPOS4 models. The charge balance functions of inclusive, pion, kaon, and proton pairs exhibit amplitudes and shapes that depend on particle species and differ significantly in the two models due to the different particle production mechanisms implemented in PYTHIA and EPOS. The shapes and amplitudes also evolve with multiplicity in both models. In addition, the evolution of the longitudinal rms width and that of balance functions integrals with multiplicity (and average transverse momentum) feature significant differences in the two models.
© The Author(s) 2025
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3.
