Inelastic electron scattering cross sections for the excited states at 6.43, 6.74, and 7.06 MeV in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ were measured with high resolution. The measurements were done in forward and backward directions covering the momentum transfer range of $0.3<q<\mathrm{}2.5\mathrm{}$ ${\mathrm{fm}}^{-1\mathrm{}}$. The state at 7.06 MeV was identified as the $\pi {\left(i_{\frac{13}{2}}{h_{\frac{11}{2}}^{-}}^1\right)}_{12-}$ and the states at 6.74 and 6.43 MeV as the $\nu {\left(j_{\frac{15}{2}}{i_{\frac{13}{2}}^{-}}^1\right)}_{14-,12-}$, respectively. The identification was based on four criteria: (a) the agreement between the $q$ dependence of the measured form factor with that of Hartree-Fock single particle-hole prediction, with no adjustment of radial parameters, (b) the absence of a longitudinal form factor, (c) the relative magnitude of the observed levels, and (d) the excitation energies being close to the single p-h energies. The measured strength of each state was found to be 50% of the single p-h prediction.

NUCLEAR REACTIONS ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$($e$,$e^{\prime }$) $E=50-335\mathrm{}$ MeV; measured $\sigma \mathrm{}\left(E\right)\mathrm{}$, $\theta =90\mathrm{}°,160\mathrm{}°$. ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ deduced, levels $J^{\pi }={12}^{-}, {14}^{-}$. DWBA calculation with Hartree-Fock single particle wave functions.

• Received 2 March 1979

DOI:https://doi.org/10.1103/PhysRevC.20.497