Core polarization for the electric quadrupole moment of neutron-rich Aluminum isotopes

TL;DR

This study investigates the core polarization effects on the electric quadrupole moments of neutron-rich aluminum isotopes near the island of inversion using a microscopic particle-vibration coupling model.

Contribution

It introduces a detailed microscopic approach combining Skyrme Hartree-Fock-Bogoliubov and QRPA to analyze polarization charges in exotic isotopes.

Findings

Polarization charge for proton 1d5/2 hole in 33Al is sensitive to neutron coupling.

Polarization charge in 35Al increases due to stronger collectivity in 36Si.

Core polarization effects vary significantly with neutron pairing and vibrational modes.

Abstract

The core polarization effect for the electric quadrupole moment of the neutron-rich $^{31}$Al, $^{33}$Al and $^{35}$Al isotopes in the vicinity of the island of inversion are investigated by means of the microscopic particle-vibration coupling model in which the Skyrme Hartee-Fock-Bogoliubov and quasiparticle-random-phase approximation are used to calculate the single-quasiparticle wave functions and the excitation modes. It is found that the polarization charge for the proton $1d_{5/2}$ hole state in $^{33}$Al is quite sensitive to coupling to the neutrons in the $pf$-shell associated with the pairing correlations, and that the polarization charge in $^{35}$Al becomes larger due to the stronger collectivity of the low-lying quadrupole vibrational mode in the neighboring $^{36}$Si nucleus.