Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the Role of the Annihilation Channel in Front Form Positronium
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga