Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Towards the theory of coherent hard dijet production on hadrons and
  nuclei   We carry out a detailed calculation of the cross section of pion diffraction
dissociation into two jets with large transverse momenta, originating from a
hard gluon exchange between the pion constituents. Both the quark and the gluon
contribution are considered and in the latter case we present calculations both
in covariant and in axial gauges. We find that the standard collinear
factorization does not hold in this reaction. The structure of non-factorizable
contributions is discussed and the results are compared with the experimental
data. Our conclusion is that the existing theoretical uncertainties do not
allow, for the time being, for a quantitative extraction of the pion
distribution amplitude.

28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th