Quadrupole moment of 14B exotic nucleus

N S Manie

doi:10.30723/ijp.v12i23.337

Abstract

    The quadrupole moment of 14B exotic nucleus has been calculated using configuration mixing shell model with limiting number of orbital's in the model space. The core- polarization effects, are included through a microscopic theory which considers a particle-hole excitations from the core and the model space orbits into the higher orbits with 6ħω excitations using M3Y interaction. The simple harmonic oscillator potential is used to generate the single particle wave functions. Large basis no-core shell model with (0+2)ћω truncation is used for 14B nucleus. The effective charges for the protons and neutrons were calculated successfully and the theoretical quadrupole moment was compared with the experimental data, which was found to be in a good agreement.   

Highlights

The study of exotic nuclei, i.e. nuclei with extreme properties, such as an extreme ratio of the number of neutrons and protons, excitation energy or total nuclear spin provides an attractive testing of nuclear structure studies
Using the OBDM elements of the model space discussed above, with the single-particle wave functions of a Harmonic oscillator potential with size parameter b =1.64fm, the calculated quadrupole moment value is 1.927efm2. This value is calculated without core polarization effect, i.e. with bare charges, and it is underestimates the measured value 2.98 ± 0.075 efm2 [27] by around a factor of 1.5, when core polarization effects are taken into consideration, the quadrupole moment becomes 2.22 efm2, which still underestimates the experimental value by around factor 1.3
In this work, we have given an overview on a specific topic which attracts much attention in contemporary nuclear structure research, namely the quadrupole moments of 14B exotic nucleus

Summary

Introduction

The study of exotic nuclei, i.e. nuclei with extreme properties, such as an extreme ratio of the number of neutrons and protons, excitation energy or total nuclear spin provides an attractive testing of nuclear structure studies. Douici et al [6] studied the effect of the particle-number projection on the electric quadrupole moment (Q2) of eveneven proton-rich nuclei in the isovector neutron-proton pairing case. An expression of the electric quadrupole moment, which takes into account the isovector neutron-proton pairing effect and which conserves the particle number, is established within the Sharp-Bardeencooper-Schrietter (SBCS) method. This expression does generalize the one used in the pairing between like-particles case. The quadrupole moment is related to the reduced transition probability B(J), as [9]; Q

CP which can be written as

Results and Discussion

Conclusions