Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Recent progress on nuclear parton distribution functions   We report current status of global analyses on nuclear parton distribution
functions (NPDFs). The optimum NPDFs are determined by analyzing high-energy
nuclear reaction data. Due to limited experimental measurements, antiquark
modifications have large uncertainties at x>0.2 and gluon modifications cannot
be determined. A nuclear modification difference between u and d quark
distributions could be an origin of the long-standing NuTeV sin^2 theta_w
anomaly. There is also an issue of nuclear modification differences between the
structure functions of charged-lepton and neutrino reactions. Next, nuclear
clustering effects are discussed in structure functions F_2^A as a possible
explanation for an anomalous result in the Be-9 nucleus at the Thomas Jefferson
National Accelerator Facility (JLab). Last, tensor-polarized quark and
antiquark distribution functions are extracted from HERMES data on the
polarized structure function b_1 of the deuteron, and they could be used for
testing theoretical models and for proposing future experiments, for example,
the one at JLab. Such measurements could open a new field of spin physics in
spin-one hadrons.

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The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
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The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph