Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Duality in semi-inclusive pion electroproduction   We explore quark-hadron duality in semi-inclusive pion electroproduction on
proton and neutron targets. Using the spin-flavor symmetric quark model, we
compute ratios of pi+ and pi- cross sections for both unpolarized and polarized
scattering, and discuss realizations of duality in several symmetry breaking
scenarios. The model calculations allow one to understand some of the key
features of recent data on semi-inclusive pion production at low energies.

21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph