Inelastic electron scattering fromCa48

Inelastic electron scattering from ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$ has been performed over a momentum transfer range from 0.6 to 3.0 ${\mathrm{fm}}^{\mathrm{-}1}$ in both forward and backward directions. Form factors have been obtained for 25 levels up to 10 MeV excitation. Charge and current densities for 11 low lying electric transitions and current densities for two magnetic transitions have been reconstructed in Fourier Bessel analysis. Three high spin states observed in the region of 9 MeV excitation are found to have the dominant configuration ν(1$g_{9/2}$,1$f_{7/2}^{\mathrm{-}1}$ ${)}_8$ ${}_{}{}^{\mathrm{-}}{}_{}{}^{}$ but with a total strength of only 36% predicted for the first $8^{\mathrm{-}}$ in a random-phase-approximation calculation. This is interpreted as evidence for particle-phonon coupling. Comparisons of the extracted densities are made with random-phase-approximation calculations using a zero-range, density-dependent Migdal interaction.