Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Coulomb displacement energies as a probe for nucleon pairing in the
  $f_{7/2}$ shell
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys