Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonperturbative and perturbative aspects of photo- and electroproduction
  of vector mesons   We discuss various aspects of vector meson production, first analysing the
interplay between perturbative and nonperturbative aspects of the QCD
calculation. Using a general method adapted to incorporate both perturbative
and nonpertubative aspects, we show that nonperturbative effects are important
for all experimentally available values of the photon virtuality Q2. We compare
the huge amount of experimental information now available with our theoretical
results obtained using a specific nonperturbative model without free
parameters, showing that quite simple features are able to explain the data.

28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics