Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Generalized Parton Distributions and Deep Exclusive Reactions: Present
  Program at JLab   We review briefly the physical concept of generalized parton distributions
and the experimental challenges associated with the corresponding measurements
of deep exclusive reactions.The first data obtained at Jefferson Lab for
exclusive photon (DVCS) and vector meson (DVMP) electroproduction above the
resonance-excitation region are described . Two upcoming dedicated DVCS
experiments are presented in some detail.

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The categories of this paper are: physics
10
The categories of this paper are: q-bio
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The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
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The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
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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: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: cond-mat
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The categories of this paper are: q-fin
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The categories of this paper are: plasm-ph
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The categories of this paper are: nlin
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-alg