Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fluctuations of anisotropic flow in Pb+Pb collisions at
  $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with the ATLAS detector   Multi-particle azimuthal cumulants are measured as a function of centrality
and transverse momentum using 470 $\mu$b$^{-1}$ of Pb+Pb collisions at
$\sqrt{s_{\mathrm{NN}}}=5.02$ TeV with the ATLAS detector at the LHC. These
cumulants provide information on the event-by-event fluctuations of harmonic
flow coefficients $v_n$ and correlated fluctuations between two harmonics $v_n$
and $v_m$. For the first time, a non-zero four-particle cumulant is observed
for dipolar flow, $v_1$. The four-particle cumulants for elliptic flow, $v_2$,
and triangular flow, $v_3$, exhibit a strong centrality dependence and change
sign in ultra-central collisions. This sign change is consistent with
significant non-Gaussian fluctuations in $v_2$ and $v_3$. The four-particle
cumulant for quadrangular flow, $v_4$, is found to change sign in mid-central
collisions. Correlations between two harmonics are studied with three- and
four-particle mixed-harmonic cumulants, which indicate an anti-correlation
between $v_2$ and $v_3$, and a positive correlation between $v_2$ and $v_4$.
These correlations decrease in strength towards central collisions and either
approach zero or change sign in ultra-central collisions. To investigate the
possible flow fluctuations arising from intrinsic centrality or volume
fluctuations, the results are compared between two different event classes used
for centrality definitions. In peripheral and mid-central collisions where the
cumulant signals are large, only small differences are observed. In
ultra-central collisions, the differences are much larger and transverse
momentum dependent. These results provide new information to disentangle flow
fluctuations from the initial and final states, as well as new insights on the
influence of centrality fluctuations.

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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: q-fin
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The categories of this paper are: physics
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn
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The categories of this paper are: mtrl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc