Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dipole Polarizabilities of $\pi^{\pm}$-Mesons   The main experimental works, where dipole polarizabilities of charged pions
have been determined, are considered. Possible reasons for the differences
between the experimental data are discussed. In particular, it is shown that
the account of the $\sigma$-meson gives a significant correction to the value
of the polarizability obtained in the latest experiment of the COMPASS
collaboration. We present also new fit results for the
$(\gamma\gamma\to\pi\pi)$ reaction.

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The categories of this paper are: chem-ph
2
The categories of this paper are: math
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
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The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph