A1 Journal article (refereed)
Study of charged particle production at high pT using event topology in pp, p–Pb and Pb–Pb collisions at √sNN = 5.02 TeV (2023)

ALICE Collaboration. (2023). Study of charged particle production at high pT using event topology in pp, p–Pb and Pb–Pb collisions at √sNN = 5.02 TeV. Physics Letters B, 843, Article 137649. https://doi.org/10.1016/j.physletb.2022.137649

JYU authors or editors

Publication details

All authors or editors: ALICE Collaboration

Journal or series: Physics Letters B

ISSN: 0370-2693

eISSN: 1873-2445

Publication year: 2023

Publication date: 15/06/2023

Volume: 843

Article number: 137649

Publisher: Elsevier

Publication country: Netherlands

Publication language: English

DOI: https://doi.org/10.1016/j.physletb.2022.137649

Research data link: https://www.hepdata.net/

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/88389

Web address of parallel published publication (pre-print): https://arxiv.org/abs/2204.10157

Abstract

This letter reports measurements which characterize the underlying event associated with hard scatterings at mid-pseudorapidity (|η| < 0.8) in pp, p–Pb and Pb–Pb collisions at centre-of-mass energy per nucleon pair, √sNN = 5.02 TeV. The measurements are performed with ALICE at the LHC. Different multiplicity classes are defined based on the event activity measured at forward rapidities. The hard scatterings are identified by the leading particle defined as the charged particle with the largest transverse momentum (pT) in the collision and having 8 < pT < 15 GeV/c. The pT spectra of associated particles (0.5 ≤ pT < 6 GeV/c) are measured in different azimuthal regions defined with respect to the leading particle direction: toward, transverse, and away. The associated charged particle yields in the transverse region are subtracted from those of the away and toward regions. The remaining jet-like yields are reported as a function of the multiplicity measured in the transverse region. The measurements show a suppression of the jet-like yield in the away region and an enhancement of high-pT associated particles in the toward region in central Pb–Pb collisions, as compared to minimum-bias pp collisions. These observations are consistent with previous measurements that used two-particle correlations, and with an interpretation in terms of parton energy loss in a high-density quark gluon plasma. These yield modifications vanish in peripheral Pb–Pb collisions and are not observed in either high-multiplicity pp or p–Pb collisions.

Keywords: particle physics

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Ministry reporting: Yes

VIRTA submission year: 2023

JUFO rating: 3