Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A study of the etapipi channel produced in central pp interactions at
  450 GeV/c   The reaction pp -> pf (eta pi pi) ps has been studied at 450 GeV/c. There is
clear evidence for an a2(1320)pi decay mode of the eta2(1645) and eta2(1870).
In addition, there is evidence for an a0(980)pi$ decay mode of both resonances
and an f2(1270)eta decay mode of the eta2(1870). No evidence is found for a JPC
= 2++ a2(1320)pi wave.

3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph