Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Structure of and E2 transition in $^{16}$C in a $^{14}$C+n+n model   A three-body model of $^{14}$C+n+n is applied to study the energy spectrum
and the hindered $E$2 transition in $^{16}$C. A realistic two-nucleon potential
is used for the valence neutrons. Both spin singlet and triplet components for
the neutrons are taken into account. The three-body problem with a Pauli
constraint is solved in a stochastic variational method. For the n-$^{14}$C
potential chosen to reproduce the properties of $^{15}$C, the low-lying energy
spectrum agrees reasonably well with experiment, but the ground state is
predicted to be about 1 MeV high. The calculated $B(E2$; $2_1^+ \to 0^+_1)$
value is about twice the measured value if the polarization charge of the
valence neutrons is taken to be the same as that required to fit the $^{15}$C
data. The correlated motion of the valence neutrons is displayed through the
two-neutron density distribution.

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The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th