Bonn 2010 – wissenschaftliches Programm
HK 64.1: Gruppenbericht
Freitag, 19. März 2010, 14:00–14:30, HG III
Latest results on hard exclusive processes at HERMES — •Sergey Yaschenko — DESY, Platanenallee 6, D-15738 Zeuthen, Germany
Hard exclusive leptoproduction of real photons (Deeply Virtual Compton Scattering, DVCS) or mesons on nucleons can be expressed in terms of Generalized Parton Distributions (GPDs). The theoretical framework of GPDs includes Parton Distribution Functions and Form Factors as limiting cases and moments of GPDs, respectively, and can provide a three-dimensional representation of the structure of hadrons at the partonic level. The HERMES experiment at DESY, Hamburg, collected a wealth of data on hard exclusive processes utilizing the HERA polarized electron or positron beams with energies of 27.6 GeV, and longitudinally and transversely polarized or unpolarized gas targets (H, D or heavier nuclei). The azimuthal asymmetries measured in DVCS and exclusive meson production allow access to information related to GPDs. An overview of the latest HERMES results on exclusive processes is presented.