Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of the $e^+e^- \to\pi^+\pi^- $ process cross section with
  the SND detector at the VEPP-2000 collider in the energy region
  $0.525<\sqrt{s}<0.883$ GeV   The cross section of the process $e^+ e^-\to\pi^+\pi^-$ has been measured in
the Spherical Neutral Detector (SND) experiment at the VEPP-2000 $e^+e^-$
collider VEPP-2000 in the energy region $525 <\sqrt[]{s} <883$ MeV. The
measurement is based on data with an integrated luminosity of about 4.6
pb$^{-1}$. The systematic uncertainty of the cross section determination is 0.8
% at $\sqrt{s}>0.600$ GeV. The $\rho$ meson parameters are obtained as $m_\rho
= 775.3\pm 0.5\pm 0.6$ MeV, $\Gamma_\rho = 145.6\pm 0.6\pm 0.8$ MeV,
$B_{\rho\to e^+ e^-}\times B_{\rho\to\pi^+\pi^-} = (4.89\pm 0.02\pm 0.04)\times
10^{-5}$, and the parameters of the $e^+ e^-\to\omega\to\pi^+\pi^-$ process,
suppressed by $G$-parity, as $B_{\omega\to e^+ e^-}\times
B_{\omega\to\pi^+\pi^-}= (1.32\pm 0.06\pm 0.02)\times 10^{-6} $ and
$\phi_{\rho\omega} = 110.7\pm 1.5\pm1.0$ degrees.

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The categories of this paper are: chem-ph
3
The categories of this paper are: physics
16
The categories of this paper are: stat
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
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The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
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The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg