Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurements of Photon and Neutral Pion Production in Heavy Ion
  Collisions at RHIC   Inclusive transverse momentum spectra of photons and neutral pions about
mid-rapidity are presented for Au+Au collisions at sqrt(s_NN} = 130 GeV. Photon
pair conversions have been reconstructed from charged tracks measured with the
central Time Projection Chamber (TPC) of STAR. Contributions of the pi^0 ->
\gamma\gamma decay in the inclusive photon spectra have been studied. It was
found that this contribution begins to decrease at a transverse momentum of
1.65 GeV/c in the top 11% most central centrality class.

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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
2
The categories of this paper are: math
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The categories of this paper are: stat
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
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The categories of this paper are: solv-int
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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org