Dispersion representations for hard exclusive reactions
Abstract
Description
A number of hard exclusive scattering processes can be described in terms of generalized parton distributions (GPDs) and perturbative hard-scattering kernels. Both the physical amplitude and the hard-scattering kernels fulfill dispersion relations. We show that their consistency at all orders in perturbation theory is guaranteed if the GPDs satisfy certain integral relations. These relations are fulfilled thanks to Lorentz invariance.
5 pages, Talk presented at the 12th Workshop on High Energy Spin Physics (DSPIN-07), Dubna, Russia, September 3--7, 2007
5 pages, Talk presented at the 12th Workshop on High Energy Spin Physics (DSPIN-07), Dubna, Russia, September 3--7, 2007