Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Single spin asymmetries and vector meson production in DIS   We discuss possible measurements and origins of single spin asymmetries in
DIS and of some unusual spin properties of vector mesons produced in lepton-
nucleon, photon-nucleon and photon-photon interactions. Such effects have
already been observed in other processes.

3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org