Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Azimuthal Asymmetries: Access to Novel Structure Functions   One of the most interesting consequence of non-zero intrinsic transverse
momentum of partons in the nucleon is the nontrivial azimuthal dependence of
the cross section of hard scattering processes. Many of the observable
asymmetries contain unknown functions which provide essential information on
the quark and gluon structure. Several of them have been studied in the last
few years; we discuss their qualitative and quantitative features in
semi-inclusive DIS.

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The categories of this paper are: chao-dyn
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: cs
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: math
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: cond-mat