A1 Journal article (refereed)
Skewness and kurtosis of mean transverse momentum fluctuations at the LHC energies (2024)

ALICE Collaboration. (2024). Skewness and kurtosis of mean transverse momentum fluctuations at the LHC energies. Physics Letters B, 850, Article 138541. https://doi.org/10.1016/j.physletb.2024.138541

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: 2024

Volume: 850

Article number: 138541

Publisher: Elsevier BV

Publication country: Netherlands

Publication language: English

DOI: https://doi.org/10.1016/j.physletb.2024.138541

Research data link: https://www.hepdata.net/record/ins2692420

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/94860

Publication is parallel published: https://arxiv.org/abs/2308.16217

Abstract

The first measurements of skewness and kurtosis of mean transverse momentum (⟨pT⟩) fluctuations are reported in Pb−Pb collisions at √sNN = 5.02 TeV, Xe−Xe collisions at √sNN= 5.44 TeV and pp collisions at s√=5.02 TeV using the ALICE detector. The measurements are carried out as a function of system size ⟨dNch/dη⟩1/3|η|<0.5, using charged particles with transverse momentum (pT) and pseudorapidity (η), in the range 0.2<3.0 GeV/c and |η|<0.8, respectively. In Pb−Pb and Xe−Xe collisions, positive skewness is observed in the fluctuations of ⟨pT⟩ for all centralities, which is significantly larger than what would be expected in the scenario of independent particle emission. This positive skewness is considered a crucial consequence of the hydrodynamic evolution of the hot and dense nuclear matter created in heavy-ion collisions. Furthermore, similar observations of positive skewness for minimum bias pp collisions are also reported here. Kurtosis of ⟨pT⟩ fluctuations is found to be in good agreement with the kurtosis of Gaussian distribution, for most central Pb−Pb collisions. Hydrodynamic model calculations with MUSIC using Monte Carlo Glauber initial conditions are able to explain the measurements of both skewness and kurtosis qualitatively from semicentral to central collisions in Pb--Pb system. Color reconnection mechanism in PYTHIA8 model seems to play a pivotal role in capturing the qualitative behavior of the same measurements in pp collisions.

Keywords: particle physics; nuclear physics; quark-gluon plasma

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Ministry reporting: Yes

VIRTA submission year: 2024

Preliminary JUFO rating: 3