Excitation of low-lying levels and giant multipole resonances inZr92,Sn120, andPb208by inelastic scattering of 104 MeV polarized protons

Abstract

Differential cross section analyzing power angular distributions have been measured for transitions to low-lying bound states and the giant resonance region in $^{92}\mathrm{Zr}$, $^{120}\mathrm{Sn}$, and $^{208}\mathrm{Pb}$, through inelastic scattering of 104 MeV polarized protons. Collective model calculations employing a complex transition potential with spin-orbit coupling reproduce the data for the low-lying states very well. The cross section and the analyzing power angular distribution data for the giant quadrupole region are better fitted if a small admixture of the $L=4$ component is added to the $L=2$ multipole. Because of lack of knowledge about the absolute strength of the isovector potential, the magnitude of the calculated cross section for the giant dipole resonance is uncertain. This has limited the accuracy with which we could determine the contribution of the giant monopole resonance which is located in the same region of excitation as the dipole resonance.