Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analyzing the nucleon spin in weak interaction processes at HERA
  energies   We investigate the possibility to measure the spin content carried by the
different quark flavors in a nucleon by means of polarized deep inelastic
scattering with $W^\pm$ exchange at HERA. Such measurements require a polarized
proton beam. The expected inclusive and semi inclusive asymmetries are sizable
and for realistic luminosities the expected statistical accuracies are good
enough to extract new and relevant information on the valence quark and the
strange sea distributions.

36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat