Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Cold neutral atoms via charge exchange from excited state positronium: a
  proposal
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con