Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radiative pion photoproduction in covariant chiral perturbation theory   We present a calculation of radiative pion photoproduction in the framework
of covariant chiral perturbation theory with explicit $\Delta(1232)$ degrees of
freedom. The analysis is performed employing the small scale expansion scheme
adjusted for the $\Delta$ region. Depending on the channel, we include
contributions up to next-to-next-to-leading order. We fit the available
experimental data for the reaction $ \gamma p\to\gamma p\pi^0 $ and extract the
value of the $\Delta^+$ magnetic moment. Errors from the truncation of the
small scale expansion are estimated using the Bayesian approach. We compare our
results both with the previous studies within the $\delta$-expansion scheme and
with the $\Delta$-less theory. We also give predictions for radiative
charged-pion photoproduction.

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The categories of this paper are: hep-th
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The categories of this paper are: q-alg
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The categories of this paper are: comp-gas
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The categories of this paper are: econ
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The categories of this paper are: physics
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The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
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The categories of this paper are: stat
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: gr-qc
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg
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The categories of this paper are: plasm-ph