Quasifree (e,e′p) reactions on nuclei with neutron excess

Abstract

We study the evolution of the (e, e p) cross section on nuclei with increasing asymmetry between the number of neutrons and protons. The calculations are done within the framework of the distorted-wave impulse approximation, by adopting nonrelativistic and relativistic models. We compare the results obtained with three different approaches based on the mean-field description for the proton bound-state wave function. In the nonrelativistic model phenomenological Woods-Saxon and Hartree-Fock wave functions are used; in the relativistic model the wave functions are solutions of Dirac-Hartree equations. The models are first tested against experimental data on 16 O, 40 Ca, and 48 Ca nuclei, and then they are applied to calculate (e, e p) cross sections for a set of spherical calcium and oxygen isotopes. From the comparison of the results obtained for the various isotopes we can infer information about the dependence of the various ingredients of the models on the neutron to proton asymmetry.

Relativistic description of final-state interactions in neutral-current neutrino and antineutrino cross sections

“…Previous studies have clearly stated the relevance of final-state interactions (FSI) to reproduce the exclusive (e, e p) cross section within the distorted-wave impulse approximation (DWIA) [28,29,[52][53][54][55][56][57] and the use of a complex optical potential (OP). The imaginary part of the OP produces an absorption that reduces the cross section and accounts partly for the loss of the incident flux to the open inelastic channels.…”

Electron-induced proton knockout from neutron rich nuclei

“…Some results are presented and discussed in the next section. More results can be found in [12] 2. Results Our DWIA calculations have been carried out with the same program DWEEPY [13,14] which was used for the analyses of the NIKHEF data.…”

“…The behavior of the s.p. hole wave functions with increasing neutron number shows a different trend for the different models [12]. The dependence of the wave functions on the proton to neutron asymmetry is responsible for only a part of the differences in the reduced cross sections.…”

Quasielastic scattering with the relativistic Green’s function approach

“…A reliable description of FSI is an essential ingredient for the comparison with data. The relevance of FSI has been clearly stated for the exclusive (e, e ′ p) reaction, where the use of complex optical potentials (OP) in the distorted-wave impulse approximation (DWIA) is required [1,2,3,4,5,6,7,8]. The imaginary part of the OP produces an absorption that reduces the cross section and accounts for the fact that, if other channels are open besides the elastic one, part of the incident flux is lost in the elastically scattered beam and goes to the other (inelastic) channels which are open.…”