Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Critical Enhancement of the In-medium Nucleon-Nucleon Cross Section at
  low Temperatures   The in-medium nucleon-nucleon cross section is calculated starting from the
thermodynamic T-matrix at finite temperatures. The corresponding
Bethe-Salpeter-equation is solved using a separable representation of the Paris
nucleon-nucleon-potential. The energy-dependent in-medium N-N cross section at
a given density shows a strong temperature dependence. Especially at low
temperatures and low total momenta, the in-medium cross section is strongly
modified by in-medium effects. In particular, with decreasing temperature an
enhancement near the Fermi energy is observed. This enhancement can be
discussed as a precursor of the superfluid phase transition in nuclear matter.

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The categories of this paper are: atom-ph
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The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
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The categories of this paper are: dg-ga
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-ex
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The categories of this paper are: cmp-lg
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The categories of this paper are: econ
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys