Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reactions gamma gamma -> pi pi and gamma gamma -> K \bar K: the
  (IJ^{PC}=00^{++})-wave spectra at E_{gamma gamma}^{(c.m.)} = 300- 1900 MeV   We calculate the $00^{++}$-wave two-meson spectra for the reactions
$\gamma\gamma\to\pi^0\pi^0$, $\gamma\gamma\to\pi^+\pi^-$, $\gamma\gamma\to
K^0\bar K^0$ and $\gamma\gamma\to K^+ K^-$ on the basis of: (i) the results of
the $K$-matrix analysis of the $00^{++}$ amplitudes for the reactions $\pi\pi
\to \pi\pi$, $K\bar K$, $\eta\eta$, $\eta\eta'$, $\pi\pi\pi\pi $, and (ii)
recently developed method for calculation of the decay amplitudes
$f_0(1^3P_0q\bar q)\to \gamma\gamma$, $f_0(2^3P_0q\bar q)\to \gamma\gamma$. The
reconstructed $\pi\pi $ and $K\bar K$ spectra can be used as a guide for the
extraction of partial widths of scalar/isoscalar resonances $f_0(980)\to
\gamma\gamma$, $f_0(1300)\to \gamma\gamma$, $f_0(1500)\to \gamma\gamma$,
$f_0(1750)\to \gamma\gamma$. As follows from our calculations, the resonances
$f_0(980)$ and $f_0(1500)$ in the $\pi^+\pi^-$ and $\pi^0\pi^0$ spectra reveal
themselves as dips.

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The categories of this paper are: math
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The categories of this paper are: solv-int
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The categories of this paper are: stat
11
The categories of this paper are: hep-lat
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The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
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The categories of this paper are: cs
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
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The categories of this paper are: nlin
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The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-th