Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Applications of Symmetry Breaking in Determining PDFs of the Nucleon   Studying the possible breaking of various parton model symmetries by the
parton distribution functions of the nucleon can provide important information
for the non-perturbative structure of hadrons and the strong interaction. We
review theoretical calculations for the breaking of flavor symmetry,
quark-antiquark symmetry and charge symmetry in the unpolarized and polarized
nucleons using the meson cloud model. We report an estimation for the total
distribution of strange and antistrange quarks in the nucleon by combining
theoretical calculations of SU(3) flavor symmetry breaking with light antiquark
distributions obtained from global analysis of available experimental data.

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The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
27
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: hep-ex
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The categories of this paper are: math
33
The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
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The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
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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: bayes-an
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The categories of this paper are: quant-ph