Centrality dependence of pion freeze-out radii in Pb-Pb collisions at sNN =2.76 TeV
- Author(s): Adam, J
- Adamová, D
- Aggarwal, MM
- Aglieri Rinella, G
- Agnello, M
- Agrawal, N
- Ahammed, Z
- Ahn, SU
- Aimo, I
- Aiola, S
- Ajaz, M
- Akindinov, A
- Alam, SN
- Aleksandrov, D
- Alessandro, B
- Alexandre, D
- Alfaro Molina, R
- Alici, A
- Alkin, A
- Almaraz, JRM
- Alme, J
- Alt, T
- Altinpinar, S
- Altsybeev, I
- Alves Garcia Prado, C
- Andrei, C
- Andronic, A
- Anguelov, V
- Anielski, J
- Antičić, T
- Antinori, F
- Antonioli, P
- Aphecetche, L
- Appelshäuser, H
- Arcelli, S
- Armesto, N
- Arnaldi, R
- Arsene, IC
- Arslandok, M
- Audurier, B
- Augustinus, A
- Averbeck, R
- Azmi, MD
- Bach, M
- Badalà, A
- Baek, YW
- Bagnasco, S
- Bailhache, R
- Bala, R
- Baldisseri, A
- Baltasar Dos Santos Pedrosa, F
- Baral, RC
- Barbano, AM
- Barbera, R
- Barile, F
- Barnaföldi, GG
- Barnby, LS
- Barret, V
- Bartalini, P
- Barth, K
- Bartke, J
- Bartsch, E
- Basile, M
- Bastid, N
- Basu, S
- Bathen, B
- Batigne, G
- Batista Camejo, A
- Batyunya, B
- Batzing, PC
- Bearden, IG
- Beck, H
- Bedda, C
- Behera, NK
- Belikov, I
- Bellini, F
- Bello Martinez, H
- Bellwied, R
- Belmont, R
- Belmont-Moreno, E
- Belyaev, V
- Bencedi, G
- Beole, S
- Berceanu, I
- Bercuci, A
- Berdnikov, Y
- Berenyi, D
- Bertens, RA
- Berzano, D
- Betev, L
- Bhasin, A
- Bhat, IR
- Bhati, AK
- Bhattacharjee, B
- Bhom, J
- Bianchi, L
- et al.
Published Web Location
https://doi.org/10.1103/PhysRevC.93.024905Abstract
© 2016 CERN. 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.