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.
| Original language | English |
|---|---|
| Article number | 024905 |
| Journal | Physical Review C - Nuclear Physics |
| Volume | 93 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 4 2016 |
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All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
Cite this
Centrality dependence of pion freeze-out radii in Pb-Pb collisions at s NN =2.76 TeV CENTRALITY DEPENDENCE of PION FREEZE-OUT ... J. ADAM et al. / ALICE Collaboration.
In: Physical Review C - Nuclear Physics, Vol. 93, No. 2, 024905, 04.02.2016.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Centrality dependence of pion freeze-out radii in Pb-Pb collisions at s NN =2.76 TeV CENTRALITY DEPENDENCE of PION FREEZE-OUT ... J. ADAM et al.
AU - ALICE Collaboration
AU - Adam, J.
AU - Adamová, D.
AU - Aggarwal, M. M.
AU - Aglieri Rinella, G.
AU - Agnello, M.
AU - Agrawal, N.
AU - Ahammed, Z.
AU - Ahn, S. U.
AU - Aimo, I.
AU - Aiola, S.
AU - Ajaz, M.
AU - Akindinov, A.
AU - Alam, S. N.
AU - Aleksandrov, D.
AU - Alessandro, B.
AU - Alexandre, D.
AU - Alfaro Molina, R.
AU - Alici, A.
AU - Alkin, A.
AU - Almaraz, J. R M
AU - Alme, J.
AU - Alt, T.
AU - Altinpinar, S.
AU - Altsybeev, I.
AU - Alves Garcia Prado, C.
AU - Andrei, C.
AU - Andronic, A.
AU - Anguelov, V.
AU - Anielski, J.
AU - Antičić, T.
AU - Antinori, F.
AU - Antonioli, P.
AU - Aphecetche, L.
AU - Appelshäuser, H.
AU - Arcelli, S.
AU - Armesto, N.
AU - Arnaldi, R.
AU - Arsene, I. C.
AU - Arslandok, M.
AU - Audurier, B.
AU - Augustinus, A.
AU - Averbeck, R.
AU - Azmi, M. D.
AU - Bach, M.
AU - Badalà, A.
AU - Baek, Y. W.
AU - Bagnasco, S.
AU - Bailhache, R.
AU - Cherney, Michael G.
AU - Seger, Janet E.
PY - 2016/2/4
Y1 - 2016/2/4
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84959387322&partnerID=8YFLogxK
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U2 - 10.1103/PhysRevC.93.024905
DO - 10.1103/PhysRevC.93.024905
M3 - Article
VL - 93
JO - Physical Review C - Nuclear Physics
JF - Physical Review C - Nuclear Physics
SN - 0556-2813
IS - 2
M1 - 024905
ER -