High-lying single-particle and single-hole states were studied using ${(}^7$Li${,}^6$Li), ${(}^7$Li${,}^6$He), ${(}^{12}$C${,}^{13}$C), and ${(}^{12}$C${,}^{13}$N) reactions at 30 MeV/nucleon on the targets ${}_{}{}^{207}{}_{}{}^{}\mathrm{Pb}$, ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$, ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$, ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, and ${}_{}{}^{91}{}_{}{}^{}\mathrm{Zr}$. Broad resonancelike features were observed in both proton and neutron transfer reactions at excitation energies close to the excitation energies of the giant quadrupole resonances. The measured excitation energies and reaction Q values suggest that these features are predominantly single-particle states rather than collective giant resonance excitations. The existence of an extra particle or hole outside closed-shell nuclei does not change the strengths of the broad peaks significantly, but does change the excitation energies in some cases. Shell model calculations in the Pb region support this conclusion.

• Received 10 August 1992

DOI:https://doi.org/10.1103/PhysRevC.47.1200