Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cross Section Measurements of Hard Diffraction at the SPS-Collider   The UA8 experiment previously reported the observation of jets in diffractive
events containing leading protons (``hard diffraction''), which was interpreted
as evidence for the partonic structure of an exchanged Reggeon, believed to be
the Pomeron . In the present Letter, we report the final UA8 hard-diffractive
(jet) cross section results and their interpretation. After corrections, the
fraction of single diffractive events with mass from 118 to 189 GeV that have
two scattered partons, each with Et_jet > 8 GeV, is in the range 0.002 to 0.003
(depending on x_p). We determine the product, fK, of the fraction by which the
Pomeron's momentum sum rule is violated and the normalization constant of the
Pomeron-Flux-Factor of the proton. For a pure gluonic- or a pure qqbar-Pomeron
, respectively: fK = 0.30 +- 0.05 +- 0.09) and (0.56 +- 0.09 +- 0.17) GeV^-2.

32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs