Vibrational 1+-, 2+-, 3+- and 4+-excitations in spherical nuclei

The moments method is applied to the description of the collective 1+-, 2+-, 3+- and 4+-excitations. Their energies are calculated in the approximation of the incompressible nucleus with a sharp edge. Good agreement with the experimental data is obtained for the centroids of the quadrupole and hexadecapole giant resonances. The centroids of more higher 2+- and 4+-resonances as well as those of the octupole magnetic and 1+-resonances are predicted. The theory gives the centroid of all the low-lying (below GQR) 2+-levels at E≅24A-1/3 MeV. It exhausts ∼20% of EWSR, the rest is exhausted by GQR together with higher 2+-states. The necessity to take into account the octupole and hexadecapole Fermi surface deformations is shown. 33 refs.; 3 figs