Electron Scattering Cross Section for Light Nuclei Within the Unified Electroweak Theory

We employ the multipole expansion within the unified electroweak theory to develop a complete calculation method of the electron scattering cross section for light nuclei. The specific calculations for 6,7Li and 7Be nuclei indicate that the conventional impulse approximation can be applied to the electron-nucleus scattering only when the incident electron energy does not exceed twice the nucleon mass. In addition, the quasielastic scattering cross section of 7Li in the excitation from its ground state to the nearest excited state and that of elastic scattering in the ground state are independently treated, whereas they have not been separately measured in experiments. The obtained scattering cross sections corresponding to an appropriate adjustment of the harmonic oscillator parameter along with the V-A structure interpret reasonably well the available experimental data at MeV energies and provide predictive information at GeV energies. This gives new perspectives in studying the structure of nuclei and the weak interactions via electron or lepton scattering at high (GeV) energies, considering nuclei rather than quarks.