Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Charge Exchange Spin-Dipole Excitations of 90Zr and 208Pb and Neutron
  Matter Equation of State   Charge exchange spin-dipole (SD) excitations of $^{90}$Zr and $^{208}$Pb are
studied by using a Skyrme
  Hartree-Fock(HF) + Random Phase approximation (RPA). The calculated
spin-dipole strength distributions are compared with experimental data obtained
by $^{90}$Zr (p,n) $^{90}$Nb and $^{90}$Zr (n,p) $^{90}$ Nb reactions. The
model-independent SD sum rule values of various Skyrme interactions are studied
in comparison with the experimental values in order to determine the neutron
skin thickness of $^{90}$Zr. The pressure of the neutron matter equation of
state (EOS) and the nuclear matter symmetry energy are discussed in terms of
the neutron skin thickness and peak energies of SD strength distributions.

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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: patt-sol
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The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
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The categories of this paper are: atom-ph
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The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
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The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc