Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Systematic trends of neutron skin thickness versus relative neutron
  excess   Available experimental neutron skin thicknesses of even-even stable Ca, Ni,
Sn, Pb, and Cd isotopes are evaluated, and separate trends of neutron skin
thickness versus relative neutron excess $\delta=(N-Z)/A$ are firstly observed
for different isotopic chains. This phenomenon is quantitatively reproduced by
the deformed Skyrme Hartree-Fock $+$ BCS model with SLy4 force.

23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas