Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The $\eta NN$-system at low energy within a three-body approach   The role of the $\eta NN$-interaction is studied in the low energy regime in
$\eta$-deuteron reactions as well as in coherent and incoherent
$\eta$-photoproduction on the deuteron using a three-body model with separable
two-body interactions. The three-body approach turns out to be quite essential
in the most important lowest partial wave. Results are presented for
differential and total cross sections as well as for the $\eta$-meson spectrum.
They differ significantly from those predicted by a simple rescattering model
in which only first-order $\eta N$- and $NN$-interactions in the final state
are considered. The major features of the experimental data of
$\eta$-photoproduction in the near-threshold region are well reproduced.

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The categories of this paper are: cs
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
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The categories of this paper are: hep-th
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The categories of this paper are: solv-int
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
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The categories of this paper are: math-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: atom-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: eess
8
The categories of this paper are: hep-ex