Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hadronic Vacuum Polarization Contribution to the Muonium Hyperfine
  Splitting   We discuss hadronic effects in the muonium hyperfine structure and derive an
expression for the hadronic contribution to the hfs interval in form of the
one-dimensional integral of the cross section of e+e- annihilation into
hadrons. Higher-order hadronic contributions are also considered.

24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
16
The categories of this paper are: stat
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org