Giant resonance studies using the reaction (e,e′γ)

We have calculated the electromagnetic decay of the giant resonance of 12C following electroexcitation. The nuclear states have been described within the framework of a 1p-1h self-consistent continuum RPA using the Skyrme-3 effective interaction. The resonant amplitude adds coherently with the electronic bremsstrahlung amplitude, which leads to angular distributions dominated by the bremsstrahlung peaks in the direction of the incident and scattered electron. In order to suppress the bremsstrahlung background and to enhance the resonant amplitude, the experiments should be performed at high energy of the incident electron, relatively small momentum transfer and for non-coplanar kinematics. In this kinematical region the predicted cross sections are of the order of 10-32 cm2 MeV · sr2 with a suppression of bremsstrahlung by about one order of magnitude over a wide angular range.