Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Possible contributions to $e^+e^- \to J/\psi + \eta_c$ due to
  intermediate meson rescatterings   Inspired by the obvious discrepancies between experiment and non-relativistic
QCD (NRQCD) studies of $e^+ e^-\to J/\psi+\eta_c$ at $\sqrt{s}\simeq 10.6$ GeV,
we investigate contributions from intermediate meson loops as long-range
interaction transitions to this process. The intermediate meson loops include
$D\bar D(\bar D^\ast)$, $D\bar D^\ast(D {or} D^\ast)$, $D^\ast \bar D^\ast(D)$
and corresponding $D_s$ intermediate mesons. With the constraints from
experimental data on the vertex couplings, we find that the intermediate meson
loops account for $2.7\sim 6.7 fb$ of the cross sections within a reasonable
range of cut-off energies of the factor parameter. We also investigate
contributions from the absorptive part and find that it accounts for
approximately $0.58\sim 1.38 fb$. These results imply that contributions from
long-range interaction transitions may still play a role in such an energy
region.

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The categories of this paper are: alg-geom
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
1
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: hep-lat
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The categories of this paper are: stat
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
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The categories of this paper are: supr-con
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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: gr-qc
3
The categories of this paper are: physics
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The categories of this paper are: astro-ph
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The categories of this paper are: acc-phys