Genuine twist-3 contributions to the generalized parton distributionsfrom instantons
Institut für Theoretische Physik II, Ruhr-Universität Bochum, 44780, Bochum, Germany
2 Petersburg Nuclear Physics Institute, 188350, Gatchina, St. Petersburg, Russia
The genuine twist-3 quark-gluon () contributions to the generalized parton distributions (GPDs) are estimated in the model of the instanton vacuum. These twist-3 effects are found to be parametrically suppressed relative to the “kinematical” twist-3 ones due to the small packing fraction of the instanton vacuum. We derived exact sum rules for the twist-3 GPDs.
© Springer-Verlag, 2004