Elastic electron scattering from 17Ne and 27P exotic nuclei

Abstract

The ground state proton, neutron and matter densities and
corresponding root mean square radii of unstable proton-rich 17Ne
and 27P exotic nuclei are studied via the framework of the twofrequency
shell model. The single particle harmonic oscillator wave
functions are used in this model with two different oscillator size
parameters core b and halo , b the former for the core (inner) orbits
whereas the latter for the halo (outer) orbits. Shell model calculations
for core nucleons and for outer (halo) nucleons in exotic nuclei are
performed individually via the computer code OXBASH. Halo
structure of 17Ne and 27P nuclei is confirmed. It is found that the
structure of 17Ne and 27P nuclei have 2
5 / 2 (1d ) and 1/ 2 2s -dominant
configurations, respectively. Elastic electron scattering form factors
of these exotic nuclei are also studied using the plane wave Born
approximation. Effects of the long tail behavior of the proton density
distribution on the proton form factors of 17Ne and 27P are
analyzed. It is found that the difference between the proton form
factor of 17Ne and that of stable 20Ne (or of 27P and that of stable
31P) comes from the difference in the proton density distribution of
the last two protons (or of the last proton) in the two nuclei. It is
concluded that elastic electron scattering will be an efficient tool (in
the near future) to examine proton-halo phenomena of proton-rich
nuclei.