Quasielastic electron scattering in the giant-resonance energy region

摘要

A new method is proposed for extracting the quasielastic portion of the spectrum of scattered electrons. The method is based on the so-called "bin" technique within which a multipole analysis is followed by a determination of the resonance shape and magnitude. The method essentially consists in performing a simultaneous multipole analysis of the mixture of quasielastic and resonance cross sections. A subsequent identification of resonance peaks in the cross section and its quasielastic portion is performed in the energy dependence of the transition probability for each multipolarity, since, there, the difference between the resonance and quasielastic processes is more pronounced than in the spectra of scattered electrons. The method makes it possible to reconstruct the process and to find the energy dependence of the quasielastic cross section in the primary spectra of scattered electrons. The spectra of quasielastically scattered electrons are obtained by the method in question for the Cu-65 nucleus. The positions of the quasielastic-peak maxima and their shift with respect to the case of scattering on a free nucleon are determined in the momentum-transfer range q = 0.5-1.2 fm(-1).