Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Long-Range Transverse-Momentum Correlations and Radial Flow in Pb-Pb Collisions at the LHC

Acharya, S. ; Basu, S. LU orcid ; Christiansen, P. LU ; Hansen, J. LU orcid ; Iversen, K.E. LU orcid ; Nepeivoda, R. LU orcid ; Ohlson, A. LU ; Panasenko, I. LU ; Silvermyr, D. LU orcid and Staa, J. LU , et al. (2026) In Physical Review Letters 136(3).
Abstract
This Letter presents measurements of long-range transverse-momentum correlations using a new observable, v0(pT), serving as a probe of event-by-event radial-flow fluctuations, the underlying radial expansion, and the medium's properties in heavy-ion collisions. Results are reported for inclusive charged particles, pions, kaons, and protons across various centrality intervals in Pb-Pb collisions at sNN=5.02 TeV, recorded by the ALICE detector. A pseudorapidity-gap technique, similar to that used in anisotropic-flow studies, is employed to suppress short-range correlations. At low pT, a characteristic mass ordering consistent with hydrodynamic collective flow is observed. At higher pT (>3 GeV/c), protons exhibit larger v0(pT) than pions... (More)
This Letter presents measurements of long-range transverse-momentum correlations using a new observable, v0(pT), serving as a probe of event-by-event radial-flow fluctuations, the underlying radial expansion, and the medium's properties in heavy-ion collisions. Results are reported for inclusive charged particles, pions, kaons, and protons across various centrality intervals in Pb-Pb collisions at sNN=5.02 TeV, recorded by the ALICE detector. A pseudorapidity-gap technique, similar to that used in anisotropic-flow studies, is employed to suppress short-range correlations. At low pT, a characteristic mass ordering consistent with hydrodynamic collective flow is observed. At higher pT (>3 GeV/c), protons exhibit larger v0(pT) than pions and kaons, in agreement with expectations from quark-recombination models. Comparisons to viscous hydrodynamic calculations with varying bulk viscosity and equation of state demonstrate the sensitivity of the v0(pT) observable to these key medium properties. The findings establish v0(pT) as a valuable addition to the set of observables used in Bayesian analyses for extracting the transport properties and constraining the equation of state of strongly interacting matter, while also helping to systematically explore its sensitivity and impact within such global studies. © 2026 CERN. (Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; and (Less)
author collaboration
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Binary alloys, Equations of state, Hadrons, Heavy ions, Hydrodynamics, Lead alloys, Particle detectors, Tellurium compounds, gluconate potassium, heavy ion, proton, Equation-of-state, Flow fluctuations, Heavy-ion collisions, Measurements of, Media properties, Momentum correlation, Pb-Pb collisions, Pseudorapidities, Radial expansions, Transverse momenta, article, controlled study, pharmacokinetics, pion, Radial flow
in
Physical Review Letters
volume
136
issue
3
article number
032302
publisher
American Physical Society
external identifiers
  • scopus:105028656957
ISSN
0031-9007
DOI
10.1103/l36g-6f46
language
English
LU publication?
yes
id
7df266e5-cf49-4ea2-9ebb-fafaabae4f49
date added to LUP
2026-04-07 14:59:16
date last changed
2026-04-08 07:54:33
@article{7df266e5-cf49-4ea2-9ebb-fafaabae4f49,
  abstract     = {{This Letter presents measurements of long-range transverse-momentum correlations using a new observable, v0(pT), serving as a probe of event-by-event radial-flow fluctuations, the underlying radial expansion, and the medium's properties in heavy-ion collisions. Results are reported for inclusive charged particles, pions, kaons, and protons across various centrality intervals in Pb-Pb collisions at sNN=5.02 TeV, recorded by the ALICE detector. A pseudorapidity-gap technique, similar to that used in anisotropic-flow studies, is employed to suppress short-range correlations. At low pT, a characteristic mass ordering consistent with hydrodynamic collective flow is observed. At higher pT (>3 GeV/c), protons exhibit larger v0(pT) than pions and kaons, in agreement with expectations from quark-recombination models. Comparisons to viscous hydrodynamic calculations with varying bulk viscosity and equation of state demonstrate the sensitivity of the v0(pT) observable to these key medium properties. The findings establish v0(pT) as a valuable addition to the set of observables used in Bayesian analyses for extracting the transport properties and constraining the equation of state of strongly interacting matter, while also helping to systematically explore its sensitivity and impact within such global studies.  © 2026 CERN.}},
  author       = {{Acharya, S. and Basu, S. and Christiansen, P. and Hansen, J. and Iversen, K.E. and Nepeivoda, R. and Ohlson, A. and Panasenko, I. and Silvermyr, D. and Staa, J. and Zurlo, N.}},
  issn         = {{0031-9007}},
  keywords     = {{Binary alloys; Equations of state; Hadrons; Heavy ions; Hydrodynamics; Lead alloys; Particle detectors; Tellurium compounds; gluconate potassium; heavy ion; proton; Equation-of-state; Flow fluctuations; Heavy-ion collisions; Measurements of; Media properties; Momentum correlation; Pb-Pb collisions; Pseudorapidities; Radial expansions; Transverse momenta; article; controlled study; pharmacokinetics; pion; Radial flow}},
  language     = {{eng}},
  number       = {{3}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review Letters}},
  title        = {{Long-Range Transverse-Momentum Correlations and Radial Flow in Pb-Pb Collisions at the LHC}},
  url          = {{http://dx.doi.org/10.1103/l36g-6f46}},
  doi          = {{10.1103/l36g-6f46}},
  volume       = {{136}},
  year         = {{2026}},
}