Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutron skin and halo in medium and heavy nuclei within the extended
  Thomas-Fermi theory   The neutron skin and halo distributions in medium and heavy nuclei are
calculated within the extended Thomas-Fermi approximation. Calculations are
carried out for the effective Skyrme-like forces using the direct variational
method. The analytical expression for the isovector shift of the rms radii
$\Delta r_{np}$ as a sum of skin- and halo-like terms is obtained. The
contribution of halo and skin terms to $\Delta r_{np}$ are found to be
approximately equal.

19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th