Charge and matter distributions and form factors of light, medium, and heavy neutron-rich nuclei

Abstract

Results of charge form factors calculations for several unstable neutron-rich isotopes of light, medium, and heavy nuclei (He, Li, Ni, Kr, Sn) are presented and compared to those of stable isotopes in the same isotopic chain. For the lighter isotopes (He and Li) the proton and neutron densities are obtained within a microscopic large-scale shell-model, while for heavier ones Ni, Kr, and Sn the densities are calculated in deformed self-consistent mean-field Skyrme HF+BCS method. We also compare proton densities to matter densities together with their rms radii and diffuseness parameter values. Whenever possible comparison of form factors, densities and rms radii with available experimental data is also performed. Calculations of form factors are carried out both in plane wave Born approximation (PWBA) and in distorted wave Born approximation (DWBA). These form factors are suggested as predictions for the future experiments on the electron-radioactive beam colliders where the effect of the neutron halo or skin on the proton distributions in exotic nuclei is planned to be studied and thereby the various theoretical models of exotic nuclei will be tested.

Nuclear skin emergence in Skyrme deformed Hartree-Fock calculations

“…We extend the analysis of nuclear sizes presented in Ref. [22] by performing a more systematic study of a larger set of exotic nuclei and calculating also neutron skin thicknesses. The calculated charge rms radii are compared with the laser or muonic atoms spectroscopy measurements of isotope shifts performed on Sn [37][38][39][40], Ni [41,42], and Kr [43] isotopes.…”

“…[17,18]) or the Hartree-Fock-Bogoliubov (HFB) method including pairing correlations [19][20][21][22][23][24]. The latter predicts well the monotonic increase of the neutron skin thickness for different chains of isotopes up to the drip line [19].…”

“…We have used three parametrizations of the Skyrme force, namely, SG2, Sk3 and SLy4, which were able to give an appropriate description of bulk properties of spherical and deformed nuclei in the past. As in our previous paper [22], we choose some medium and heavy Ni, Kr, and Sn isotopes, because many of these sets, which lie in the nuclear chart between the proton and neutron drip lines, can be formed as radioactive ions to perform scattering experiments. The main goal of this study is to clarify theoretically the emergence of the neutron and proton skins in neutron-rich and neutron-deficient isotopes, respectively, by testing different definitions for the skin thickness in the framework of the deformed Skyrme HF+BCS model.…”

Electron scattering form factors from exotic nuclei

“…Therein densities obtained from no-core shell model calculations [5,6] also were used. With the He isotopes, they found that the charge density of 6 He differed from that of 4 He but that of 8 He was not significantly different to that of 6 He. They also noted that the proton density does extend far with increasing neutron number.…”

Symmetry energy and surface properties of neutron-rich exotic nuclei

“…We choose some spherical medium and heavy Ni (A=74-84) and Sn (A=124-152) isotopes (considered also in Refs. [19,20]) because, first, they are primary candidates to be measured at the upcoming experimental facilities, and second, for them several predictions have been made concerning the nuclear skin emergence. In addition, we present some results for a chain of Pb (A=202-214) isotopes being inspired by the significant interest (in both experiment [21,22,23] and theory [24,25,26,27]) to study, in particular, the neutron distribution of 208 Pb and its rms radius.…”