One-nucleon-transfer reactions induced byNe20at 500 and 600 MeV

The ${(}^{20}$Ne${,}^{19}$Ne), ${(}^{20}$Ne${,}^{21}$Ne), and ${(}^{20}$Ne${,}^{21}$Na) reactions on ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ have been investigated at 500 and 600 MeV incident energies. Experimental spectra have been compared with predictions of distorted-wave Born approximation calculations. The different shapes observed for proton and neutron pickup spectra are explained quite well by the calculations. In particular, the broad peak observed at about 6.5 MeV in the ${(}^{20}$Ne${,}^{21}$Ne) spectra is shown to originate from ejectile excitation in the 1${\mathit{d}}_{3/2}$, 1${\mathit{f}}_{7/2}$, and 2${\mathit{p}}_{3/2}$ orbitals. An important component of the ${(}^{20}$Ne${,}^{19}$Ne) cross section is due to three-body processes, such as the elastic breakup of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ into ${}_{}{}^{19}{}_{}{}^{}\mathrm{Ne}$ and one neutron. In addition, bumps are observed at about 1.5 and 10 MeV excitation energy in ${}_{}{}^{209}{}_{}{}^{}\mathrm{Pb}$ and 2.5 and 14 MeV in ${}_{}{}^{91}{}_{}{}^{}\mathrm{Zr}$. The low energy peaks are shown to originate mainly from neutron transfer to high spin orbitals, i.e., 1${\mathit{i}}_{11/2}$ and 1${\mathit{j}}_{15/2}$ in ${}_{}{}^{209}{}_{}{}^{}\mathrm{Pb}$ and 1${\mathit{g}}_{7/2}$ and 1${\mathit{h}}_{11/2}$ in ${}_{}{}^{91}{}_{}{}^{}\mathrm{Zr}$. Because of the selectivity of the ${(}^{20}$Ne,