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Centrality dependence of pion freeze-out radii in Pb-Pb collisions at sNN =2.76 TeV

J., Adam ; Christiansen, P. LU ; Ljunggren, H. LU ; Oskarsson, A. LU ; Richert, T. LU ; Silvermyr, D. LU orcid ; Søgaard, C. LU ; Stenlund, E. LU ; Vislavicius, V. LU and M., Zyzak (2016) In Physical Review C 93(2).
Abstract
We report on the measurement of freeze-out radii for pairs of identical-charge pions measured in Pb-Pb collisions at sNN=2.76 TeV as a function of collision centrality and the average transverse momentum of the pair kT. Three-dimensional sizes of the system (femtoscopic radii), as well as direction-averaged one-dimensional radii are extracted. The radii decrease with kT, following a power-law behavior. This is qualitatively consistent with expectations from a collectively expanding system, produced in hydrodynamic calculations. The radii also scale linearly with (dNch/dη)1/3. This behavior is compared to world data on femtoscopic radii in heavy-ion collisions. While the dependence is qualitatively similar to results at smaller sNN, a... (More)
We report on the measurement of freeze-out radii for pairs of identical-charge pions measured in Pb-Pb collisions at sNN=2.76 TeV as a function of collision centrality and the average transverse momentum of the pair kT. Three-dimensional sizes of the system (femtoscopic radii), as well as direction-averaged one-dimensional radii are extracted. The radii decrease with kT, following a power-law behavior. This is qualitatively consistent with expectations from a collectively expanding system, produced in hydrodynamic calculations. The radii also scale linearly with (dNch/dη)1/3. This behavior is compared to world data on femtoscopic radii in heavy-ion collisions. While the dependence is qualitatively similar to results at smaller sNN, a decrease in the ratio Rout/Rside is seen, which is in qualitative agreement with a specific prediction from hydrodynamic models: a change from inside-out to outside-in freeze-out configuration. The results provide further evidence for the production of a collective, strongly coupled system in heavy-ion collisions at the CERN Large Hadron Collider. © 2016 CERN. (Less)
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author collaboration
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review C
volume
93
issue
2
article number
024905
publisher
American Physical Society
external identifiers
  • scopus:84959387322
ISSN
2469-9985
DOI
10.1103/PhysRevC.93.024905
language
English
LU publication?
yes
id
a4cd240d-14c8-4178-8409-4be842133200
date added to LUP
2022-04-04 13:47:24
date last changed
2025-10-14 12:41:22
@article{a4cd240d-14c8-4178-8409-4be842133200,
  abstract     = {{We report on the measurement of freeze-out radii for pairs of identical-charge pions measured in Pb-Pb collisions at sNN=2.76 TeV as a function of collision centrality and the average transverse momentum of the pair kT. Three-dimensional sizes of the system (femtoscopic radii), as well as direction-averaged one-dimensional radii are extracted. The radii decrease with kT, following a power-law behavior. This is qualitatively consistent with expectations from a collectively expanding system, produced in hydrodynamic calculations. The radii also scale linearly with (dNch/dη)1/3. This behavior is compared to world data on femtoscopic radii in heavy-ion collisions. While the dependence is qualitatively similar to results at smaller sNN, a decrease in the ratio Rout/Rside is seen, which is in qualitative agreement with a specific prediction from hydrodynamic models: a change from inside-out to outside-in freeze-out configuration. The results provide further evidence for the production of a collective, strongly coupled system in heavy-ion collisions at the CERN Large Hadron Collider. © 2016 CERN.}},
  author       = {{J., Adam and Christiansen, P. and Ljunggren, H. and Oskarsson, A. and Richert, T. and Silvermyr, D. and Søgaard, C. and Stenlund, E. and Vislavicius, V. and M., Zyzak}},
  issn         = {{2469-9985}},
  language     = {{eng}},
  number       = {{2}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review C}},
  title        = {{Centrality dependence of pion freeze-out radii in Pb-Pb collisions at sNN =2.76 TeV}},
  url          = {{http://dx.doi.org/10.1103/PhysRevC.93.024905}},
  doi          = {{10.1103/PhysRevC.93.024905}},
  volume       = {{93}},
  year         = {{2016}},
}