Quasielastic electron scattering from nuclei

Abstract

Inelastic electron scattering is studied in terms of the “characteristic function” F( t), i.e., the Fourier transform of the response function with respect to the energy transfer to the nucleus. Analytic properties of F( t) are discussed as well as moment and cumulant expansions. The latter are particularly useful in the region of the quasielastic peak where the first few characterize position, width and shape of the peak. The dependence of these observables on ground state properties and the final state interaction between ejected nucleon and residual nucleus is calculated for a variety of models. It is shown that the observed shift of the quasielastic peak is related to the exchange parts of the two-body interaction or equivalently to the nonlocality of the optical potential. Semiclassical methods are used to derive a generalized Fermi gas model for inclusive scattering which includes the final state interaction in a simple way. Numerical results are presented for quasielastic electron scattering from 12C. A similar description within the framework of a relativistic nuclear field theory gives surprisingly good agreement with experiment for medium and heavy nuclei and points out the advantages of a relativistic treatment.