Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: What Can We Learn from Transverse Momentum Spectra in Relativistic Heavy
  Ion Collisions?   We compare the predictions of different models for transverse momentum
spectra in relativistic heavy ion collisions. Particular emphasis is given to
hydrodynamic flow with different assumptions for the radial expansion, and to
models based on a superposition of fireballs along the transverse direction
(random walk). It is shown that present experimental data cannot distinguish
between the models under consideration.

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The categories of this paper are: quant-ph
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The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
16
The categories of this paper are: stat
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
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: bayes-an
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex