Density distributions and form factors of the exotic 8B nucleus

W Z Majeed

doi:10.30723/ijp.v11i20.379

Abstract

Results of charge, neutron and matter densities and related form factors for one- proton halo nucleus 8B are presented using a two- frequency shell model approach. We choose a model space for the core of 7Be different from that of the extra one valence proton. One configuration is assumed for the outer proton to be in 1p1/2 - shell. The results of the matter density distributions are compared with those fitted to the experimental data. The calculated proton and matter density distributions of this exotic nucleus exhibit a long tail behavior, which is considered as a distinctive feature of halo nuclei. Elastic electron scattering form factors of this exotic nucleus are also studied. The effects of the proton halo on the electron scattering form factors are analyzed. The form factors of the exotic unstable 8B nucleus are compared with those of the stable 10B nucleus. The differences between the results of unstable 8B and stable 10B nuclei come from the long tail in the density distribution of the last proton.

Highlights

Nuclear halo has been an interesting topic in nuclear physics since the discovery of the halo effect in 11Li [1]
As the halo nuclei are oversized and broken system consisting of a compact core plus a number of outer nucleons loosely bound and especially extended far from the core, it is suitable to separate the ground state density distribution of Eq (14) into two parts, one is connected with the core nucleons and the other one with the hole nucleons, so the matter density distribution for the whole halo nucleus becomes:
The charge, neutron and matter densities for this nucleus can be calculated in the framework of the two frequency shell model, with two different oscillator size parameters bcore for the core orbits and bhalo for the proton halo orbit

Summary

Introduction

Nuclear halo has been an interesting topic in nuclear physics since the discovery of the halo effect in 11Li [1]. Large space shell model wave functions have been assumed They emphasized that the effect of the proton halo, in the case of 8B, is very evident with the decrease in the form factor with momentum transfer reflecting the more extensive charge distribution. Et al study of nuclear structure, for the study of electromagnetic properties of nuclei It has given much consistent information on proton density distributions of stable nuclei. The electron-nucleus scattering is a better technique for the accurate study of the long tail behavior in the nucleon density distribution of the exotic rich nuclei. In the present work, form factors of exotic 8B nucleus are studied with PWBA corresponding to the density distributions obtained by the two-frequency shell model.

Ti Tz

Results and Discussion

Conclusions