Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nuclear Quark and Gluon Distributions in Coordinate Space   In coordinate space, quark and gluon distributions of the nucleon are defined
as correlation functions involving two field operators separated by a
light-cone distance $y^+ = 2l$. We study the nuclear modifications of these
distributions. The largest effect is a strong depletion of parton distributions
(shadowing) at large longitudinal distances, which starts for all parton
species at $l=2$ fm, i.e. at the average nucleon-nucleon separation in nuclei.
On the other hand, the nuclear radius does not play a significant role. At $l
\lsim 1$ fm, nuclear modifications of parton distributions are small. The
intrinsic structure of individual nucleons is evidently not very much affected
by nuclear binding. In particular, there is no evidence for a significant
increase of the quark or gluon correlation length in bound nucleons.

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The categories of this paper are: solv-int
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The categories of this paper are: stat
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: atom-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-fin