Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Octet Spin Fractions and the Proton Spin Problem   The relatively small fraction of the spin of the proton carried by its quarks
presents a major challenge to our understanding of the strong interaction.
Traditional efforts to explore this problem have involved new and imaginative
experiments and QCD based studies of the nucleon. We propose a new approach to
the problem which exploits recent advances in lattice QCD. In particular, we
extract values for the spin carried by the quarks in other members of the
baryon octet in order to see whether the suppression observed for the proton is
a general property or depends significantly on the baryon structure. We compare
these results with the values for the spin fractions calculated within a model
that includes the effects of confinement, relativity, gluon exchange currents
and the meson cloud required by chiral symmetry, finding a very satisfactory
level of agreement given the precision currently attainable.

23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
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The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
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The categories of this paper are: eess
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat