Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Particle number conserving BCS approach in the relativistic mean field
  model and its application to $^{32-74}$Ca
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn