Hard photons and energetic protons as probes of the nuclear dynamics at intermediate energy

The emission of hard photons and pre-equilibrium protons has been investigated in exclusive experiments performed with MEDEA detector. The observation of the γ-proton anticorrelation indicates that the dominant production mechanism is the first-chance neutron-proton (np) collisions. The anisotropic angular distributions point out the presence of screening effects and are reminiscent of the free np scattering thus giving information of the space-time origin of the energetic protons. Protons, with energy more than twice the kinematical limit for nucleon-nucleon (NN) collisions, have been observed in several reactions around the Fermi energy.