Elastic Electron Scattering From Unstable Neutron-Rich 19C Exotic Nucleus


The ground state proton, neutron, and matter density distributions and corresponding root-mean-square (rms) of 19C exotic nucleus are studied in terms of two-frequency shell model (TFSM) approach. The single-particle wave functions of harmonic-oscillator (HO) potential are used with two different oscillator parameters bcore and bhalo. According to this model, the core nucleons of 18C nucleus are assumed to move in the model space of spsdpf. The shell model calculations are carried out for core nucleons with truncations using the realistic WBP interaction. The outer (halo) neutron in 19C is assumed to move in the pure 2s1/2-orbit. The halo structure in 19C is confirmed with 2s1/2-dominant configuration. Elastic electron scattering form factor of 19C nucleus is also investigated by means of the Plane Wave Born approximation. The effect of the long tail behavior (found in the calculated matter density distribution) on the elastic form factor of 19C is studied. The calculated matter densities and form factors of stable 13C and unstable 19C are compared. It is found that the difference between the nucleon form factors of 13C and 19C nuclei is attributed to the difference presented in the matter densities of these nuclei. Hence the difference in the matter densities of 19C and 13C nuclei mainly comes from the neutron skin of the core 18C and from the difference in the neutron density distribution of the last one neutron in both 19C and 13C nuclei. It is found that elastic electron scattering from exotic nuclei can provide predictions for the near future experiments on the electron-radioactive beam colliders where the effect of the neutron halo or skin on the charge distributions is planned to be studied.PACS number(s): 25.60.Dz, 21.10.Gv, 27.30.+t, 13.14.Gp.