Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cusps in K --> 3 pi decays   The pion mass difference generates a pronounced cusp in K --> 3 pi decays. As
has recently been pointed out by Cabibbo and Isidori, an accurate measurement
of the cusp may allow one to pin down the S-wave pi pi scattering lengths to
high precision. Here, we present and illustrate an effective field theory
framework that allows one to determine the structure of this cusp in a
straightforward manner. The strictures imposed by analyticity and unitarity are
respected automatically.

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The categories of this paper are: supr-con
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The categories of this paper are: atom-ph
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The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: physics
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th
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The categories of this paper are: nlin
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The categories of this paper are: econ
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The categories of this paper are: comp-gas