Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Two-particle azimuthal correlations as a probe of collective behaviour
  in deep inelastic $\textit{ep}$ scattering at HERA
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
18
The categories of this paper are: econ
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics