Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Trajectory of neutron$-$neutron$-^{18}C$ excited three-body state   The trajectory of the first excited Efimov state is investigated by using a
renormalized zero-range three-body model for a system with two bound and one
virtual two-body subsystems. The approach is applied to $n-n-^{18}$C, where the
$n-n$ virtual energy and the three-body ground state are kept fixed. It is
shown that such three-body excited state goes from a bound to a virtual state
when the $n-^{18}$C binding energy is increased. Results obtained for the
$n-^{19}$C elastic cross-section at low energies also show dominance of an
$S-$matrix pole corresponding to a bound or virtual Efimov state. It is also
presented a brief discussion of these findings in the context of ultracold atom
physics with tunable scattering lengths.

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The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
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The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
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The categories of this paper are: cs
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The categories of this paper are: eess
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-fin
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The categories of this paper are: astro-ph
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an