Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: THE PROTON SPIN PUZZLE AND DEPOLARIZATION IN
  $\bar{p}p\to\bar{\Lambda}\Lambda$   We point out that the measurement of target spin depolarization $D_{nn}$ in
the $\bar{p}p\to\bar{\Lambda}\Lambda$ reaction may test dynamical mechanisms
invoked to explain the proton spin puzzle revealed by polarized deep--inelastic
scattering experiments. In particular, models with {\it negatively} polarized
$\bar{s}s$ pairs in the proton wave function predict $D_{nn}<0$, whereas models
with {\it positively} polarized gluons would predict $D_{nn}>0$.

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The categories of this paper are: cs
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The categories of this paper are: mtrl-th
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The categories of this paper are: math
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: astro-ph
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga
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The categories of this paper are: q-bio
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The categories of this paper are: acc-phys