Nuclear Structure and Intermediate Energy Hadron Probes: Excitation of High Energy Multipole Resonances by Inelastic Scattering of 340 MeV and 480 MeV alpha -Particle

摘要

We have used alpha particle beams of 340 MeV and 480 MeV bombarding isotopically enriched sup 208 Pb, sup 116 Sn and sup 58 Ni targets to explore with good confidence the nuclear structure of the continuum. In that study, we have used a consistent way for extracting the back-ground. We have made a multipole decomposition of the spectra, without any assumption on shape and position of the resonances. We have found a good agreement with previous studies for the low part of the spectra, and make a full exploration of the previously suspected hexadecapole peak. In the 3h omega we have shown the presence of L=5 strength, and put at it exact value the L=1 compression mode, for the three studied nuclei. Moreover, we have indications of L=4 and L=2 resonances in the 4h omega mode, and possibly of L=5 and 3 numbers of the 5h omega modes: they should be compression modes. Then, it seems, that, with intermediate energies with good statistics and coherent ways of treating the data, we have been able to see the highest excitations predicted by the models. (ERA citation 09:034671)