https://doi.org/10.1140/epjc/s10052-008-0833-x
Regular Article - Theoretical Physics
The target asymmetry in hard vector-meson electroproduction and parton angular momenta
1
Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, 141980, Moscow region, Russia
2
Fachbereich Physik, Universität Wuppertal, 42097, Wuppertal, Germany
3
Institut für Theoretische Physik, Universität Regensburg, 93040, Regensburg, Germany
* e-mail: kroll@physik.uni-wuppertal.de
Received:
8
October
2008
Published online:
13
December
2008
The target asymmetry for electroproduction of vector mesons is investigated within the handbag approach. While the generalized parton distribution (GPD) H is taken from a previous analysis of the electroproduction cross section, we here construct the GPD E from double distributions and constrain it by the Pauli form factors of the nucleon, positivity bounds and sum rules. Predictions for the target asymmetry are given for various vector mesons and it is discussed how experimental data on the asymmetry will further constrain E and what we may learn about the angular momenta the partons carry.
© Springer-Verlag , 2009
