Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Signals of the QCD axion with mass of 17 MeV/c^2: nuclear transitions
  and light meson decays
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci