Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Model-independent constraints on spin observables   We discuss model-independent constraints on spin observables in exclusive and
inclusive reactions, with special attention to the case of photoproduction.

15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math