Excitation of giant resonances in 20Ne + 90Zr and 208Pb inelastic scattering at 40 MeV/u

Spectromètre SPEG; The giant resonance region in the inelastic spectra from the reactions 20Ne + 90Zr and 20Ne + 208Pb at 40 MeV/nucleon has been studied with good energy and angular resolutions. The strength distributions of the different multipolarities contributing to the cross section were obtained without making any hypothesis on the excitation energies and shapes of the resonances. In the case of 208Pb the GDR strength was found to be strongly shifted towards lower excitation energies which can be explained by the exponentially decreasing Coulomb excitation probability. Furthermore, indications for a high multipolarity component in the resonance structure were found in both reactions.