Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic
  Scattering from the Reaction $^{3}\mathrm{He}^{\uparrow}(e,e')X$   We report the first measurement of the target-normal single-spin asymmetry in
deep-inelastic scattering from the inclusive reaction
$^3$He$^{\uparrow}\left(e,e' \right)X$ on a polarized $^3$He gas target.
Assuming time-reversal invariance, this asymmetry is strictly zero in the Born
approximation but can be non-zero if two-photon-exchange contributions are
included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron
beam, covers a range of $1.7 < W < 2.9$ GeV, $1.0<Q^2<4.0$ GeV$^2$ and
$0.16<x<0.65$. Neutron asymmetries were extracted using the effective nucleon
polarization and measured proton-to-$^3$He cross section ratios. The measured
neutron asymmetries are negative with an average value of $(-1.09 \pm 0.38)
\times10^{-2}$ for invariant mass $W>2$ GeV, which is non-zero at the
$2.89\sigma$ level. Our measured asymmetry agrees both in sign and magnitude
with a two-photon-exchange model prediction that uses input from the Sivers
transverse momentum distribution obtained from semi-inclusive deep-inelastic
scattering.

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The categories of this paper are: quant-ph
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The categories of this paper are: hep-th
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an
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The categories of this paper are: cond-mat
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The categories of this paper are: econ
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The categories of this paper are: adap-org
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The categories of this paper are: math
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The categories of this paper are: q-alg
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The categories of this paper are: cs
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The categories of this paper are: plasm-ph
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The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn
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The categories of this paper are: comp-gas
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The categories of this paper are: patt-sol