Energy dependence and fluctuations of anisotropic flow in Pb-Pb collisions at sNN=5.02 and 2.76 TeV
A bstract Measurements of anisotropic flow coefficients with two- and multi-particle cumulants for inclusive charged particles in Pb-Pb collisions at s N N = 5.02 and 2.76 TeV are reported in the pseudorapidity range | η | < 0.8 and transverse momentum 0.2 < p T < 50 GeV/ c . The full data...
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Published in | The journal of high energy physics Vol. 2018; no. 7 |
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Main Authors | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English Norwegian |
Published |
Berlin/Heidelberg
Springer Berlin Heidelberg
16.07.2018
Institute of Physics Publishing (IOPP) |
Subjects | |
Online Access | Get full text |
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Summary: | A
bstract
Measurements of anisotropic flow coefficients with two- and multi-particle cumulants for inclusive charged particles in Pb-Pb collisions at
s
N
N
=
5.02
and 2.76 TeV are reported in the pseudorapidity range |
η
| < 0.8 and transverse momentum 0.2 <
p
T
< 50 GeV/
c
. The full data sample collected by the ALICE detector in 2015 (2010), corresponding to an integrated luminosity of 12.7 (2.0)
μ
b
−1
in the centrality range 0-80%, is analysed. Flow coefficients up to the sixth flow harmonic (
v
6
) are reported and a detailed comparison among results at the two energies is carried out. The
p
T
dependence of anisotropic flow coefficients and its evolution with respect to centrality and harmonic number
n
are investigated. An approximate power-law scaling of the form
v
n
(
p
T
) ∼
p
T
n
/3
is observed for all flow harmonics at low
p
T
(0.2 <
p
T
< 3 GeV/
c
). At the same time, the ratios
v
n
/
v
m
n
/
m
are observed to be essentially independent of
p
T
for most centralities up to about
p
T
= 10 GeV/
c
. Analysing the differences among higher-order cumulants of elliptic flow (
v
2
), which have different sensitivities to flow fluctuations, a measurement of the standardised skewness of the event-by-event
v
2
distribution
P
(
v
2
) is reported and constraints on its higher moments are provided. The Elliptic Power distribution is used to parametrise
P
(
v
2
), extracting its parameters from fits to cumulants. The measurements are compared to different model predictions in order to discriminate among initial-state models and to constrain the temperature dependence of the shear viscosity to entropy-density ratio. |
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ISSN: | 1029-8479 1029-8479 |
DOI: | 10.1007/JHEP07(2018)103 |