Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: High precision measurement of ultraweak transitions of the
  a${^1}{\triangle}_g{\leftarrow}$X $^3{\Sigma}^{-}_g$ $(0,0)$ band of
  molecular oxygen
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ