Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quark correlation functions in deep inelastic semi-inclusive processes   We investigate one-particle semi-inclusive processes in lepton-hadron
scattering. In unpolarized scattering order $Q^{-1}$ corrections appear only
when transverse momenta are detected. We consider the twist two and three
matrix elements and calculate the semi-inclusive structure functions in terms
of quark correlation functions. We find that at twist three level not only the
standard quark distribution and fragmentation function contribute, but also two
new transverse "profile functions". We demonstrate explicit gauge invariance of
the hadronic tensor at the twist three level. The results of our approach are
used to calculate expressions for some cross sections for semi-inclusive
processes.

30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con