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Longitudinal and azimuthal evolution of two-particle transverse momentum correlations in Pb-Pb collisions at √sNN= 2.76 TeV

Acharya, S. ; Adolfsson, J. LU ; Christiansen, P. LU ; Matonoha, O. LU ; Nassirpour, A.F. LU orcid ; Ohlson, A. LU ; Oskarsson, A. LU ; Richert, T. LU ; V. Rueda, O. LU and Silvermyr, D. LU orcid , et al. (2020) In Physics Letters B 804.
Abstract
This paper presents the first measurements of the charge independent
(CI) and charge dependent (CD) two-particle transverse momentum
correlators G2CI and G2CD in Pb–Pb collisions at √SNN=2.76 TeV by the ALICE collaboration. The two-particle transverse momentum correlator G2 was introduced as a measure of the momentum current transfer between
neighboring system cells. The correlators are measured as a function of
pair separation in pseudorapidity (Δη) and azimuth (Δφ) and as a function of collision centrality. From peripheral to central collisions, the correlator G2CI exhibits a longitudinal... (More)
This paper presents the first measurements of the charge independent
(CI) and charge dependent (CD) two-particle transverse momentum
correlators G2CI and G2CD in Pb–Pb collisions at √SNN=2.76 TeV by the ALICE collaboration. The two-particle transverse momentum correlator G2 was introduced as a measure of the momentum current transfer between
neighboring system cells. The correlators are measured as a function of
pair separation in pseudorapidity (Δη) and azimuth (Δφ) and as a function of collision centrality. From peripheral to central collisions, the correlator G2CI exhibits a longitudinal broadening while undergoing a monotonic azimuthal narrowing. By contrast, G2CD exhibits a narrowing along both dimensions. These features are not
reproduced by models such as HIJING and AMPT. However, the observed
narrowing of the correlators from peripheral to central collisions is
expected to result from the stronger transverse flow profiles produced
in more central collisions and the longitudinal broadening is predicted
to be sensitive to momentum currents and the shear viscosity per unit of
entropy density η/s of the matter produced in the collisions. The observed broadening is
found to be consistent with the hypothesized lower bound of η/s and is in qualitative agreement with values obtained from anisotropic flow measurements. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physics Letters B
volume
804
article number
135375
pages
13 pages
publisher
Elsevier
external identifiers
  • scopus:85082403717
ISSN
0370-2693
DOI
10.1016/j.physletb.2020.135375
language
English
LU publication?
yes
id
2b93375e-e57b-47c8-a001-547ae3602ae3
date added to LUP
2021-04-12 16:00:02
date last changed
2023-04-02 06:37:25
@article{2b93375e-e57b-47c8-a001-547ae3602ae3,
  abstract     = {{This paper presents the first measurements of the charge independent <br>
(CI) and charge dependent (CD) two-particle transverse momentum <br>
correlators <i>G</i><sub>2</sub><sup>CI</sup> and G<sub>2</sub><sup>CD</sup> in Pb–Pb collisions at √<i>S</i><sub>NN</sub>=2.76 TeV by the ALICE collaboration. The two-particle transverse momentum correlator <i>G</i><sub>2 </sub>was introduced as a measure of the momentum current transfer between <br>
neighboring system cells. The correlators are measured as a function of <br>
pair separation in pseudorapidity (Δ<em>η</em>) and azimuth (Δ<em>φ</em>) and as a function of collision centrality. From peripheral to central collisions, the correlator G<sub>2</sub><sup>CI</sup> exhibits a longitudinal broadening while undergoing a monotonic azimuthal narrowing. By contrast, G<sub>2</sub><sup>CD</sup> exhibits a narrowing along both dimensions. These features are not <br>
reproduced by models such as HIJING and AMPT. However, the observed <br>
narrowing of the correlators from peripheral to central collisions is <br>
expected to result from the stronger transverse flow profiles produced <br>
in more central collisions and the longitudinal broadening is predicted <br>
to be sensitive to momentum currents and the shear viscosity per unit of<br>
 entropy density <i>η</i>/<i>s</i> of the matter produced in the collisions. The observed broadening is <br>
found to be consistent with the hypothesized lower bound of <i>η</i>/<i>s</i> and is in qualitative agreement with values obtained from anisotropic flow measurements.}},
  author       = {{Acharya, S. and Adolfsson, J. and Christiansen, P. and Matonoha, O. and Nassirpour, A.F. and Ohlson, A. and Oskarsson, A. and Richert, T. and V. Rueda, O. and Silvermyr, D. and Stenlund, E. and Zurlo, N.}},
  issn         = {{0370-2693}},
  language     = {{eng}},
  month        = {{03}},
  publisher    = {{Elsevier}},
  series       = {{Physics Letters B}},
  title        = {{Longitudinal and azimuthal evolution of two-particle transverse momentum correlations in Pb-Pb collisions at √<i>s</i><sub>NN</sub>= 2.76 TeV}},
  url          = {{http://dx.doi.org/10.1016/j.physletb.2020.135375}},
  doi          = {{10.1016/j.physletb.2020.135375}},
  volume       = {{804}},
  year         = {{2020}},
}