Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: \eta\ transitions between charmonia with meson loop contributions   We study the $\eta$ transitions between $\psi(4040/4160)$ and $J/\psi$ by
introducing charmed meson loops in an effective Lagrangian approach to enhance
the decay amplitudes. The branching fractions $\mathcal{B}[\psi(4040) \to
J/\psi \eta]$ and $\mathcal{B}[\psi(4160) \to J/\psi \eta]$ estimated in this
paper can remarkably explain the experimental measurements of Belle and BESIII
within a reasonable parameter range. The $\eta^\prime$ transition between
$\psi(4160)$ and $J/\psi$ is also investigated, and the branching fraction is
under the upper limit of CLEO, which can be tested by future experiments.

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The categories of this paper are: eess
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
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The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: solv-int
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs