Investigations of azimuthal asymmetry in semi-inclusive leptoproduction

K.A. Oganessyan; H.R. Avakian; N. Bianchi; P. Di Nezza

doi:doi:10.1007/s100529800873

EPJ

a
b
d
e
ap
st
h
plus

2019 Impact factor 4.389

Particles and Fields

Eur. Phys. J. C 5, 681-685
DOI 10.1007/s100529800873

Investigations of azimuthal asymmetry
in semi-inclusive leptoproduction

K.A. Oganessyan - H.R. Avakian - N. Bianchi - P. Di Nezza

LNF-INFN, C.P. 13, Enrico Fermi 40, Frascati, Italy (e-mail: kogan@lnf.infn.it, avakian@lnf.infn.it, bianchi@lnf.infn.it, dinezza@lnf.infn.it)

Received: 24 October 1997 / Revised version: 10 February 1998 / Published online: 26 March 1998

Abstract
We consider the azimuthal asymmetries in semi-inclusive deep inelastic leptoproduction arising due to both perturbative and nonperturbative effects at HERMES energies and show that the k_T²/Q² order corrections to $\langle \cos\phi \rangle$ and $\langle \cos2\phi \rangle$ are significant. We also reconsider the results of perturbative effects for $\langle \cos\phi \rangle$ at large momentum transfers [1] using the more recent sets of scale-dependent distribution and fragmentation functions, which bring up to $18{\%}$ difference in $\langle \cos\phi \rangle$ . In the same approach we calculate the $\langle \cos2\phi \rangle$ as well.