Deeply virtual compton scattering off an unpolarised hydrogen target using the recoil detector at HERMES

[摘要] Deeply Virtual Compton Scattering (DVCS) provides the simplest access to Generalised Parton Distributions (GPDs), which is a theoretical framework that describes nucleon structure. The GPDs are of particular interest due to the fact that they can provide a 3–dimensional description of the nucleon structure and can be used to determine the total angular momentum of quarks inside the nucleon. The DVCS interaction can be accessed via its interference with the Bethe-Heitler process, which is an experimentally indistinguishable process. At Hermes, asymmetries in the distribution of the real photon around the azimuthal angle for DVCS are measured. The beam–helicity asymmetry amplitudes are extracted from DVCS events with an unpolarised target during the 2006–2007 data taking period. This measurement made use of the final upgrade to the Hermes experiment, the Re- coil Detector. This upgrade ensured a truly exclusive DVCS measurement could be made by measuring the recoiling proton.

[发布机构] University:University of Glasgow;Department:School of Physics and Astronomy

[关键词] QC Physics