Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Diffractive Photoproduction of Z0   The two gluon exchange model of the pomeron is used to compute the
photoproduction reaction $\gamma p \to Z^0 p$. The predicted cross section is
too small to be observed at HERA, but may be detectable at an eventual Next
Linear Collider.

35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
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
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci