Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pion Content of the Nucleon in Polarized Semi-Inclusive D.I.s   An explicit pionic component of the nucleon may be identified by measuring
polarized $\Delta^{++}$ fragments produced in deep-inelastic scattering off
polarized protons. The pion-exchange model predicts highly correlated
polarizations of the $\Delta^{++}$ and target proton, in marked contrast with
the competing diquark fragmentation process.

30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
3
The categories of this paper are: physics
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas