Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: QCD improved parton distribution functions of ${\mathbf{\gamma^*_L}}$   QCD corrections to the QED formula for parton distribution functions of the
longitudinal virtual photon are derived in the leading--logarithmic
approximation. It is shown that the resulting PDF satisfy the same homogeneous
evolution equations as those of hadrons, but contrary to the latter are
perturbatively calculable. Properties of these distribution functions are
discussed and their phenomenological consequences outlined.

7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess