Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of Double cc bar Production in e+ e- Annihilation at sqrt{s}
  ~ 10.6 GeV   We report the observation of prompt J/psi via double ccbar production from
the e+e- continuum. In this process one ccbar pair fragments into a J/psi meson
while the remaining pair either produces a bound charmonium state or fragments
into open charm. Both cases have been observed: the first by studying the mass
spectrum of the system recoiling against the J/psi, and the second by
reconstructing the J/psi together with a charmed meson. We find cross-sections
of \sigma(e+ e- -> J/psi eta_c (gamma)) * BR (eta_c -> >=4 charged) = 0.033
(+0.007 -0.006)(stat) \pm 0.009(syst)pb and \sigma(e+ e- -> J/psi D*+ X) = 0.53
(+0.19 -0.15)(stat) \pm 0.14(syst) pb, and infer \sigma(e+ e- -> J/psi c cbar)
/ \sigma(e+ e- -> J/psi X) = 0.59 (+0.15 -0.13)(stat) \pm 0.12(syst). These
results are obtained from a 46.2/fb data sample collected near the Upsilon(4S)
resonance, with the Belle detector at the KEKB asymmetric energy e+ e-
collider.

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The categories of this paper are: stat
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The categories of this paper are: cond-mat
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The categories of this paper are: cs
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The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
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The categories of this paper are: econ
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The categories of this paper are: dg-ga
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The categories of this paper are: gr-qc
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The categories of this paper are: chao-dyn
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The categories of this paper are: math
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-th
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The categories of this paper are: comp-gas
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
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The categories of this paper are: mtrl-th