Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inclusive transverse momentum distributions of charged particles in
  diffractive and non--diffractive photoproduction at HERA   Inclusive transverse momentum spectra of charged particles in photoproduction
events in the laboratory pseudorapidity range $-1.2<\eta<1.4$ have been
measured up to $p_{T}=8\GeV $ using the ZEUS detector. Diffractive and
non--diffractive reactions have been selected with an average $\gamma p$ centre
of mass (c.m.) energy of $\langle W \rangle = 180\GeV$. For diffractive
reactions, the $p_{T}$ spectra of the photon dissociation events have been
measured in two intervals of the dissociated photon mass with mean values
$\langle M_{X} \rangle = 5$ GeV and $10$ GeV. The inclusive transverse momentum
spectra fall exponentially in the low $p_{T}$ region. The non--diffractive data
show a pronounced high $p_{T}$ tail departing from the exponential shape. The
$p_{T}$ distributions are compared to lower energy photoproduction data and to
hadron--hadron collisions at a similar c.m. energy. The data are also compared
to the results of a next--to--leading order QCD calculation.

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The categories of this paper are: hep-lat
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The categories of this paper are: cs
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The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
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The categories of this paper are: q-fin
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: eess
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The categories of this paper are: math-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: econ