Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inclusive production of D*+- mesons in photon-photon collisions at
  sqrt(s) = 183 and 189 GeV and a first measurement of the the charm structure
  function of the photon   The inclusive production of D*+- mesons in photon-photon collisions has been
measured using the OPAL detector at LEP at e+e- centre-of-mass energies of 183
and 189GeV. The D* mesons are reconstructed in their decay to D0pi+ with the D0
observed in the two decay modes Kpi+ and Kpi+pi-pi+. After background
subtraction, 100.4+-12.6(stat) D*+- mesons have been selected in events without
observed scattered beam electron ("anti-tagged") and 29.8+-5.9 (stat) D*+-
mesons in events where one beam electron is scattered into the detector
("single-tagged"). Direct and single-resolved events are studied separately.
Differential cross-sections as functions of the D* transverse momentum p_t and
pseudorapidity \eta are presented in the kinematic region 2<p_t<12GeV and
\eta<1.5. They are compared to next-to-leading order (NLO) perturbative QCD
calculations. The total cross-section for the process (e+e- to e+e-ccbar),
where the charm quarks are produced in the collision of two quasi-real photons,
is measured to be 842+-97(stat)+-75(syst)+-196(extrapolation)pb. A first
measurement of the charm structure function F2 of the photon is performed in
the kinematic range 0.0014<x<0.87 and 5<Q^2<100 GeV^2, and the result is
compared to a NLO perturbative QCD calculation.

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The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
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The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
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The categories of this paper are: quant-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph