Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search for Direct Photons from $\sqrt{s_{NN}}=200GeV$ AuAu Collisions
  Using a New $\pi^{0}$ Tagging Method in the PHENIX Experiment at RHIC   Direct photons provide a insightful tool to study the different stages of a
heavy ion collision, especially the formation of a quark-gluon plasma, without
being influenced by the strong interaction and hadronization processes. The
yield of direct photons can be determined based on the inclusive photon yield
and the background from hadronic decays. We present a new analysis technique
applied to PHENIX Run4 Au+Au dataset. It uses strict particle
identification(PID) in the Electromagnetic Calorimeter(EMCal) and a charged
particle veto to extract a clean photon signal. These photons are then tagged
with EMCal photon candidates with loose PID cuts, which can be reconstructed
with high efficiency, to determine the fraction of photons originating from
$\pi^{0}$ decays. Many systematic uncertainties and detector effects cancel in
this method.

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The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
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The categories of this paper are: q-fin
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The categories of this paper are: nlin
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The categories of this paper are: ao-sci
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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: supr-con
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th
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The categories of this paper are: stat
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The categories of this paper are: hep-ph
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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: adap-org
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The categories of this paper are: patt-sol