Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Precise Measurements of Beam Spin Asymmetries in Semi-Inclusive $\pi^0$
  production   We present studies of single-spin asymmetries for neutral pion
electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV
polarized electrons from an unpolarized hydrogen target, using the CEBAF Large
Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator
Facility. A substantial $\sin \phi_h$ amplitude has been measured in the
distribution of the cross section asymmetry as a function of the azimuthal
angle $\phi_h$ of the produced neutral pion. The dependence of this amplitude
on Bjorken $x$ and on the pion transverse momentum is extracted with
significantly higher precision than previous data and is compared to model
calculations.

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The categories of this paper are: quant-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: physics
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The categories of this paper are: nlin
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The categories of this paper are: solv-int
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The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: eess