Virtual Compton Scattering in the Nucleon Resonance Region

This thesis is a study of virtual Compton scattering reaction in which a virtual photon is elastically scattered off a proton γv p → γp. The p( e,e′p)γ reaction was measured in the nucleon resonance region for the first time in the experiment E93-050 in Hall A at Thomas Jefferson National Accelerator Facility. To lowest order in αQED, this reaction is a coherent superposition of radiation from the incident or scattered electron in elastic ep scattering (Bethe-Heitler) and exclusive production of a photon on the proton, by absorption of a virtual photon (virtual Compton scattering). In E93-050, we measured a resonance excitation scan for nine central values of s from 1.3 GeV2 to 3.6 GeV2, with the coincidence angular kinematics centered on θγγ = π. Part of the data analysis was also calibration of the Hall A spectrometer pair optics. Besides the experimental data analysis, a theoretical calculation of this cross-section in a phenomenological Lagrangian approach was setup. Preliminary experimental cross-section results and present status of theoretical calculation are shown here