Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Physics of Heavy Ions Collisions: The Summary of Moriond-97   CERN dilepton experiments have provided the most exciting data. Strong
enhancement at low masses observed by CERES and HELIOS3 indicate strong
modification in the vector channel in matter compared to vacuum properties.
NA50 data on $J/\psi$ suppression in PbPb collisions show surprising deviation
from the previous trend. The question is whether it is the expected early-time
signal of QGP, or due to late-time hadronic interactions.
  Theoretical and experimental suggestions have been made to resolve this
issue. BNL and SPS experiments have also provided rather complete data with
heavy beams (Au and Pb, respectively). Very strong collective flow effects have
been observed at both energies, which allow for the first time to restrict the
EOS of the hadronic matter. Several observables (flow, Coulomb effects and HBT)
suggest rather long evolution of systems created in heavy ion collisions and
very low freeze-out densities relative to previous studies. Theory of jet
stopping in QGP is becoming quantitative.

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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
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The categories of this paper are: comp-gas
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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: dg-ga
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The categories of this paper are: alg-geom
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
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The categories of this paper are: q-bio
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th