Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low energy scattering with a nontrivial pion   An earlier calculation in a generalized linear sigma model showed that the
well-known current algebra formula for low energy pion pion scattering held
even though the massless Nambu Goldstone pion contained a small admixture of a
two-quark two-antiquark field. Here we turn on the pion mass and note that the
current algebra formula no longer holds exactly. We discuss this small
deviation and also study the effects of an SU(3) symmetric quark mass type term
on the masses and mixings of the eight SU(3) multiplets in the model. We
calculate the s wave scattering lengths, including the beyond current algebra
theorem corrections due to the scalar mesons, and observe that the model can
fit the data well. In the process, we uncover the way in which linear sigma
models give controlled corrections (due to the presence of scalar mesons) to
the current algebra scattering formula. Such a feature is commonly thought to
exist only in the non-linear sigma model approach.

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The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: cond-mat
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The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
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The categories of this paper are: hep-lat
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The categories of this paper are: gr-qc
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The categories of this paper are: comp-gas
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: q-fin
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The categories of this paper are: ao-sci
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The categories of this paper are: supr-con
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The categories of this paper are: math-ph