Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: ABC effect as a signal of chiral symmetry restoration in hadronic
  collisions   A new nonconventional mechanism for the basic 2{\pi}-fusion reaction pn -->
d+({\pi}{\pi})_0 in the energy region T_p = 1.0-1.4 GeV is suggested. The
mechanism is aimed at providing a consistent explanation for the comprehensive
experimental studies of this reaction in exclusive setting done recently by the
WASA-at-COSY Collaboration. The basic assumption of the model proposed is the
production of the I(JP) = 0(3+) dibaryon resonance D03 in the pn collision. The
interference of two decay channels of this resonance: D_03 --> d + {\sigma} -->
d + ({\pi}{\pi})_0 and D_03 --> D_12 + {\pi} --> d + ({\pi}{\pi})_0 is shown to
give a strong near-threshold enhancement in the {\pi}{\pi} invariant mass
spectrum, which is well known as the ABC effect. The {\sigma}-meson parameters
found to reproduce the ABC enhancement are in a general agreement with models
which predict the chiral symmetry restoration at high excitation energy and/or
high density of matter, although they are essentially less than those accepted
for the free {\sigma} meson. So, this result might be considered as an
indication of partial chiral symmetry restoration in dense and excited quark
matter.

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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
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The categories of this paper are: econ
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: quant-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: cond-mat
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The categories of this paper are: eess
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The categories of this paper are: acc-phys