Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Parton-distribution functions for the pion and kaon in the
  gauge-invariant nonlocal chiral-quark model   We investigate the parton-distribution functions (PDFs) for the positively
charged pion and kaon at a low-renormalization scale ~ 1 GeV. To this end, we
employ the gauge-invariant effective chiral action from the nonlocal
chiral-quark model, resulting in that the vector currents are conserved. All
the model parameters are determined phenomenologically with the normalization
condition for PDF and the empirical values for the pseudoscalar-meson
weak-decay constants. We consider the momentum dependence of the effective
quark mass properly within the model calculations. It turns out that the
leading local contribution provides about 70 % of the total strength for PDF,
whereas the nonlocal one that is newly taken into account in this work for the
gauge invariance does the rest. High-Q^2 evolution to 27 GeV^2 is performed for
valance-quark distribution function (VQDF), using the DGALP equation. The
moments for the pion and kaon VQDFs are also computed. The numerical results
are compared with the empirical data and theoretical estimations, and show
qualitatively agreement with them.

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The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
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The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
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The categories of this paper are: econ
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
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The categories of this paper are: solv-int
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The categories of this paper are: eess