Coupled-channels analyses for large-angle quasi-elastic scattering in massive systems
Abstract
We discuss in detail the coupled-channels approach for the large-angle quasi-elastic scattering in massive systems, where many degrees of freedom may be involved in the reaction. We especially investigate the effects of single, double and triple phonon excitations on the quasi-elastic scattering for 48Ti,54Cr,56Fe,64Ni and 70Zn+208Pb systems, for which the experimental cross sections have been measured recently. We show that the present coupled-channels calculations well account for the overall width of the experimental barrier distribution for these systems. In particular, it is shown that the calculations taking into account single quadrupole phonon excitations in 48Ti and triple octupole phonon excitations in 208Pb reasonably well reproduce the experimental quasi-elastic cross section and barrier distribution for the 48Ti+208Pb reaction. On the other hand, 54Cr,56Fe,64Ni and 70Zn+208Pb systems seem to require the double quadrupole phonon excitations in the projectiles in order to reproduce the experimental data.