Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-Meson Form Factors in Unitarized Chiral Perturbation Theory   We present a comprehensive analysis of form factors for two light
pseudoscalar mesons induced by scalar, vector, and tensor quark operators. The
theoretical framework is based on a combination of unitarized chiral
perturbation theory and dispersion relations. The low-energy constants in
chiral perturbation theory are fixed by a global fit to the available data of
the two-meson scattering phase shifts. Each form factor derived from unitarized
chiral perturbation theory is improved by iteratively applying a dispersion
relation. This study updates the existing results in the literature and
explores those that have not been systematically studied previously, in
particular the two-meson tensor form factors within unitarized chiral
perturbation theory. We also discuss the applications of these form factors as
mandatory inputs for low-energy phenomena, such as the semi-leptonic decays
$B_s\to \pi^+\pi^-\ell^+\ell^-$ and the $\tau$ lepton decay
$\tau\rightarrow\pi^{-}\pi^{0}\nu_{\tau}$, in searches for physics beyond the
Standard Model.

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The categories of this paper are: nucl-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
26
The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
2
The categories of this paper are: math
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
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The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
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The categories of this paper are: nlin
7
The categories of this paper are: hep-th