Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Prompt Photon Production at HERA and LEP   Results on isolated prompt photon production are presented. The measurements
were performed at HERA in deep inelastic ep scattering and photoproduction, as
well as at LEP in photon photon collisions. Differential cross sections are
shown for inclusive prompt photons and those accompanied by a jet. The results
are compared to predictions of perturbative QCD calculations in next to leading
order and to predictions of the event generators PYTHIA and HERWIG.

22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs