LONGITUDINAL RESPONSE FUNCTIONS FOR CA-40 FROM QUASI-ELASTIC ELECTRON-SCATTERING

Longitudinal response functions were extracted from quasi-elastic elec tron scattering data on Ca-40 at angles of 45.5-degrees, 90-degrees, a nd 140-degrees with bombarding energies ranging from 130 to 840 MeV an d for constant three-momentum transfers of 300, 330, 370, 410 and 450 MeV/c. Contrary to previously reported results, the present longitudin al response functions show no more than 20% missing strength when comp ared to the relativistic Fermi gas model. Calculations employing wavef unctions generated from a relativistic Hartree potential and using an effective momentum approximation yield results that are in much closer agreement with the experimental data and indicate essentially no long itudinal suppression.