Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hard Probe of Geometry and Fluctuations in Heavy Ion Collisions at
  $\sqrt{s_{_{NN}}}=$ 0.2, 2.76, and 5.5 TeV   [Background:] A significant quenching of high energy jets was observed in the
heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) facility,
and is now confirmed at the Large Hadron Collider (LHC) facility. The RHIC plus
LHC era provides a unique opportunity to study the jet-medium interaction that
leads to the jet quenching, and the medium itself at different collision
energies (medium temperatures).
  [Purpose:] We study the azimuthal anisotropy of jet quenching, to seek
constraints on different models featuring distinct path-length and density
dependences for jet energy loss, and to gain a better understanding of the
medium.
  [Methods:] The models are fixed by using the RHIC data, and then applied to
study the LHC case. A set of harmonic (Fourier) coefficients $v_{n}$ are
extracted from the jet azimuthal anisotropy on a event-by-event basis.
  [Results:] The second harmonics $v_{2}$, mostly driven by the medium's
geometry, can be used to differentiate jet quenching models. Other harmonics
are also compared with the LHC (2.76 TeV) data. The predictions for future LHC
(5.5 TeV) run are presented.
  [Conclusions:] We find that a too strong path-length dependence (e.g., cubic)
is ruled out by the LHC $v_{2}$ data, while the model with a strong near-$T_c$
enhancement for the jet-medium interaction describes the data very well. It is
worth pointing out that the latter model expects a less color-opaque medium at
LHC.

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The categories of this paper are: eess
2
The categories of this paper are: math
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
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The categories of this paper are: supr-con
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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
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The categories of this paper are: astro-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn
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The categories of this paper are: cs
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The categories of this paper are: hep-ex
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The categories of this paper are: nlin