Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photoproduction of $\omega$ mesons on nuclei near the production
  threshold   The photoproduction of $\omega$ mesons on LH_2, C and Nb has been studied for
incident photon energies from 900 to 1300 MeV using the CB/TAPS detector at
ELSA. The $\omega$ line shape does not show any significant difference between
the LH_2 and the Nb targets. The data are compared with results of transport
calculations that predict a sensitivity of the $\omega$ line shape to in-medium
modifications near the production threshold on a free nucleon of
$E_{\gamma}^{lab}$ = 1109 MeV.}

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The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
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The categories of this paper are: eess
10
The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th