On the excitation of fragments of low-energy giant resonances in some light and intermediate mass nuclei at (α,α')- and (p-vector, p') scattering

It is shown how the giant quadrupole resonance (GQR) and the low-energy octupole resonance (LEOR) are fragmented into many states distributed over a wide excitation energy interval. The GQR region in 24Mg and the LEOR region in 90Zr are studied. The GQR proves to be above the neutron separation energy, while the LEOR is a bound state. It has been shown that the obtained fragments of the low-energy resonances, as well as the low-lying collective states are generally in agreement with the standard hydrodynamical model which assumes equal neutron and proton vibrations. It is demonstrated in the 90Zr(p-vector, p')90ZR* process that Iπ -4+ states are also observed in the same excitation region as the LEOR