Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Soft and Diffractive Phenomena   Recent results on hard diffraction at HERA and the Tevatron are presented.
Charged particle multiplicities in diffraction and differences in multiplicity
in quark and gluon jets measured at LEP are discussed. Spin effects in the
fragmentation of leading quarks show some interesting features.

0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin