New experimental results supporting the hypothesis of the excitation of collective modes in the 40Ca+40Ca reaction

Steps in the γ-ray multiplicity as function of the excitation energy have been observed in coincidence with the incompletely relaxed part of the energy spectra of fragments emitted in the reaction 40Ca+40Ca at 400 MeV. Excitation energies and angular dependence of these variations suggest that they are correlated with the excitation of high energy collective modes through a rather direct process in the early stages of the reaction. l-values of this excitation mode are discussed