Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin content of constituent quarks and one-spin asymmetries in inclusive
  processes   We consider mechanism for one-spin asymmetries observed in inclusive hadron
production. The main role belongs to the orbital angular momentum of the
quark-antiquark cloud in the internal structure of constituent quarks. We argue
that the origin of the asymmetries in pion production is a result of retaining
of this internal angular orbital momentum by the perturbative phase of QCD
under transition from the non-perturbative phase. The non-perturbative hadron
structure is based on the results of chiral quark models. PACS number(s):
11.30.Qc, 12.40.Pp, 13.75.Ni, 13.88.+e

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The categories of this paper are: math
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The categories of this paper are: quant-ph
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
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The categories of this paper are: nucl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: nlin
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: cmp-lg
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The categories of this paper are: supr-con
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The categories of this paper are: alg-geom