Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Production of bound triplet $\mu^{+} \mu^{-}$ system in collisions of
  electrons with atoms   This paper deals with the production of orthodimuonium (OM) ($\mu^{+}
\mu^{-}$ atom in triplet state) in collisions of high-energy electrons with
nuclei or atoms. This reaction was previously studied by Holvik and Olsen
[Phys. Rev. D 35, 2124 (1987)] on the basis of a bremsstrahlung mechanism where
OM is produced by only one virtual photon. In the present paper we consider a
competing three-photon mechanism where the production of OM results from the
collision of a photon generated by the electron with two photons emitted by the
nucleus. We derive the corresponding spectrum and production rate of OM and
show that the three-photon mechanism is the dominant one for heavy atom target.

11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn