The Hall A Deeply Virtual Compton Scattering (DVCS) experiment used the 5.757 GeV polarized electron beam available at Jefferson Laboratory and ran from september until december 2004. Using the standard Hall A left high resolution spectrometer three kinematical points were taken at a fixed xbjorken = 0.32 value for three Q2 values : 1.5 GeV 2, 1.91GeV 2, 2.32 GeV 2. An electromagnetic Lead Fluoride calorimeter and a proton detector scintillator array designed to work at a luminosity of 1037cm−2s−1 were added to ensure the exclusivity of the DVCS reaction. In addition to the new detectors new custom electronics was used : a calorimeter trigger module which determines if a electron photon coincidence has occured and a sampling system allowing to deal with pile-up events during the offline analysis. Finally the data from the kinematic at Q2=2.32 GeV2 et s=5.6GeV2 allowed to get a preliminary result for the exclusive π0 electroproduction on the proton.
Experimental setup for deeply virtual Compton scattering (DVCS) experiment in hall A at Jefferson Laboratory