Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An experimental review on heavy flavor $v_{2}$ in heavy-ion collision   For over a decade now, the primary purpose of relativistic heavy-ion
collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron
Collider (LHC) has been to study the properties of QCD matter under extreme
conditions -high temperature and high density. The heavy-ion experiments at
both RHIC and LHC have recorded a wealth of data in p+p, p+Pb, d+Au, Cu+Cu,
Cu+Au, Au+Au, Pb+Pb and U+U collisions at energies ranging from $\sqrt{s_{NN}}$
= 7.7 GeV to 7 TeV. Heavy quarks are considered good probe to study the QCD
matter created in relativistic collisions due to their very large mass and
other unique properties. A precise measurement of various properties of heavy
flavor hadrons provides an insight into the fundamental properties of the hot
and dense medium created in these nuclei-nuclei collisions, such as transport
coefficient and thermalization and hadronization mechanisms. The main focus of
this paper is to present a review on the measurements of azimuthal anisotropy
of heavy flavor hadrons and to outline the scientific opportunities in this
sector due to future detector upgrade. We will mainly discuss the elliptic flow
of open charmed meson ($D$-meson), $J/\psi$ and leptons from heavy flavor decay
at RHIC and LHC energy.

30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th