Observation of12−Magnetic Spin States inPb208

Abstract

States at 6.42-, 6.75-, and 7.06-MeV excitation have been observed in electron scattering on ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. The transverse character of the excitation cross section has been established. The states have been interpreted as the $\nu {\left({i_{\frac{13}{2}}}^{-1\mathrm{}}{j}_{\frac{15}{2}}\right)}_{{12}^{-},{14}^{-}}$ and the $\pi {\left(h_{\frac{11}{2}}{}_{}{}^{-1\mathrm{}}{}_{}{}^{}i_{\frac{13}{2}}^{}{}_{}{}^{}\right)}_{{12}^{-}}$ single-particle hole excitations of the ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ ground state, on the basis of the measured momentum-transfer dependence and the magnitude of the cross section.