Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analysis of the proton longitudinal structure function from the gluon
  distribution function   We make a critical, next-to-leading order, study of the relationship between
the longitudinal structure function FL and the gluon distribution proposed in
Cooper- Sarkar et al. (Z. Phys. C 39:281, 1988; Acta Phys. Pol. B 34:2911
2003), which is frequently used to extract the gluon distribution from the
proton longitudinal structure function at small x. The gluon density is
obtained by expanding at particular choices of the point of expansion and
compared with the hard Pomeron behavior for the gluon density. Comparisons with
H1 data are made and predictions for the proposed best approach are also
provided.

2
The categories of this paper are: math
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin