A1 Journal article (refereed)
Measurements of long-range two-particle correlation over a wide pseudorapidity range in p–Pb collisions at √sNN = 5.02 TeV (2024)
ALICE Collaboration. (2024). Measurements of long-range two-particle correlation over a wide pseudorapidity range in p–Pb collisions at √sNN = 5.02 TeV. Journal of High Energy Physics, 2024(1), Article 199. https://doi.org/10.1007/JHEP01(2024)199
JYU authors or editors
Publication details
All authors or editors: ALICE Collaboration
Journal or series: Journal of High Energy Physics
ISSN: 1126-6708
eISSN: 1029-8479
Publication year: 2024
Publication date: 31/01/2024
Volume: 2024
Issue number: 1
Article number: 199
Publisher: Springer Science and Business Media LLC
Publication country: Germany
Publication language: English
DOI: https://doi.org/10.1007/JHEP01(2024)199
Publication open access: Openly available
Publication channel open access: Open Access channel
Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/94659
Publication is parallel published: https://arxiv.org/abs/2308.16590
Abstract
Correlations in azimuthal angle extending over a long range in pseudorapidity between particles, usually called the "ridge" phenomenon, were discovered in heavy-ion collisions, and later found in pp and p−Pb collisions. In large systems, they are thought to arise from the expansion (collective flow) of the produced particles. Extending these measurements over a wider range in pseudorapidity and final-state particle multiplicity is important to understand better the origin of these long-range correlations in small-collision systems. In this Letter, measurements of the long-range correlations in p−Pb collisions at √sNN=5.02 TeV are extended to a pseudorapidity gap of Δη∼8 between particles using the ALICE, forward multiplicity detectors. After suppressing non-flow correlations, e.g., from jet and resonance decays, the ridge structure is observed to persist up to a very large gap of Δη∼8 for the first time in p−Pb collisions. This shows that the collective flow-like correlations extend over an extensive pseudorapidity range also in small-collision systems such as p−Pb collisions. The pseudorapidity dependence of the second-order anisotropic flow coefficient, v2(η), is extracted from the long-range correlations. The v2(η) results are presented for a wide pseudorapidity range of −3.1<η<4.8 in various centrality classes in p−Pb collisions. To gain a comprehensive understanding of the source of anisotropic flow in small-collision systems, the v2(η) measurements are compared to hydrodynamic and transport model calculations. The comparison suggests that the final-state interactions play a dominant role in developing the anisotropic flow in small-collision systems.
Keywords: particle physics
Contributing organizations
Related projects
- The strong interaction at the frontier of knowledge: fundamental research and applications- STRONG -2020
- Lappi, Tuomas
- European Commission
- Center of Excellence in Quark Matter
- Räsänen, Sami
- Research Council of Finland
- Center of Excellence in Quark Matter
- Kim, Dong
- Research Council of Finland
Ministry reporting: Yes
Reporting Year: 2024
Preliminary JUFO rating: 3