High-spin states ofJπ=12−, 14−inPb208studied by (e,e′)

Abstract

Inelastic electron scattering cross sections for the excited states at 6.43, 6.74, and 7.06 MeV in /sup 208/Pb were measured with high resolution. The measurements were done in forward and backward directions covering the momentum transfer range of 0.3 < q < 2.5 fm/sup -1/. The state at 7.06 MeV was identified as the ..pi.. (i/sub 13/2/h/sub 11/2//sup-1/)/sub 12/- and the states at 6.74 and 6.43 MeV as the ..nu.. (j/sub 15/2/i/sub 13/2//sup -1/)/sub 14/-/sub ,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.