Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of azimuthal asymmetries in neutral current deep inelastic
  scattering at HERA   The distribution of the azimuthal angle of charged and neutral hadrons
relative to the lepton plane has been studied for neutral current deep
inelastic $ep$ scattering using an integrated luminosity of 45 pb-1 taken with
the ZEUS detector at HERA. The measurements were made in the hadronic
centre-of-mass system. The analysis exploits the energy-flow method, which
allows the measurement to be made over a larger range of pseudorapidity
compared to previous results. The dependence of the moments of the azimuthal
distributions on the pseudorapidity and minimum transverse energy of the
final-state hadrons are presented. Although the predictions from
next-to-leading-order QCD describe the data better than do the Monte Carlo
models incorporating leading-logarithm parton showers, they still fail to
describe the magnitude of the asymmetries. This suggests that higher-order
calculations may be necessary to describe these data.

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The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
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The categories of this paper are: eess
14
The categories of this paper are: math-ph