Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Onset of Deconfinement in Pb+Pb Collisions at the Cern SPS   The NA49 fixed-target experiment studied high energy-density matter produced
in nucleus-nucleus reactions at the CERN SPS. In central Pb+Pb collisions at
158A GeV the energy density at the early stage substantially exceeds the
threshold for quark deconfinement predicted by lattice QCD. The produced matter
shows strong transverse and longitudinal flow. Ratios of yields of produced
particles are approximately consistent with statistical equilibration. An
energy scan through the SPS range revealed structure in the energy dependence
of pion and kaon yields as well as of the inverse slopes of transverse mass
distributions. These features suggest that a deconfined phase starts to be
produced at around 30A GeV in central Pb+Pb collisions. The analysis of
fluctuations and correlations has not yet provided evidence for the predicted
critical point of QCD.

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The categories of this paper are: hep-lat
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The categories of this paper are: cmp-lg
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The categories of this paper are: nlin
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The categories of this paper are: chem-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: econ
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The categories of this paper are: acc-phys
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The categories of this paper are: math
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The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph