Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Interpretation of the NA51 Experiment   We study the $p-n$ Drell-Yan asymmetry, recently measured by the NA51
collaboration, and conclude that the value quoted by their experiment only sets
a lower limit on the asymmetry of the proton sea. In particular, we notice that
charge symmetry breaking between the proton and the neutron may produce
corrections which should be taken into account.

33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex