Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Heavy Flavor in Photoproduction at HERA   Recent results on charm and beauty photoproduction at HERA are discussed. The
perturbative QCD calculations are generally smaller than the measured cross
sections, particularly in the forward (proton) direction. The study of charm
dijet photoproduction is consistent with a significant contribution of charm
excitation processes.

0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph