Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low-energy isoscalar dipole response of heavy nuclei within kinetic
  model   The low-energy isoscalar dipole response of heavy spherical nuclei is studied
by using a semiclassical model, based on the solution of the linearized Vlasov
kinetic equation for finite Fermi systems. In this translation-invariant model
the excitations of the center of mass motion are exactly separated from the
internal ones. The low-energy dipole strength function displays three resonance
structures in the energy region up to 15 MeV. Calculations of the velocity
fields associated with the resonance structures at the centroid energies show a
vortex (toroidal) character of two overlying resonances, while the origin of
the lowest isoscalar dipole resonance structure is related to the dipole
single-particle excitations. Its centroid energy is close to the minimum energy
of the dipole single-particle spectrum. The main toroidal resonance gives a
qualitative description of the low-energy isoscalar dipole resonance observed
in heavy spherical nuclei.

27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
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The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
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The categories of this paper are: eess
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an