Skyrme-QRPA calculations for low-lying excitation modes in deformed neutron-rich nuclei

Abstract

Low-frequency modes of excitation in deformed neutron-rich nuclei are studied by means of the quasiparticle random-phase approximation on the Skyrme-Hartree-Fock-Bogoliubov mean field. We investigate the microscopic structure of the soft $K^{\pi }=0^{+}$ modes systematically in neutron-rich Magnesium isotopes with $N=22,24,26$ and 28 close to the drip line, and it is found that the strong collectivity in ${}^{34}$Mg and ${}^{40}$Mg is acquired due to the coherent coupling between the $\beta$ vibration and the pairing vibration of neutrons. Microscopic structure of the $K^{\pi }=2^{+}$ modes changes gradually associated with the location of the Fermi level of neutrons, and it is found that the proton particle-hole excitation generating the $\gamma -$vibrational mode in ${}^{24}$Mg continues to play a key role in the near-drip-line nucleus ${}^{40}$Mg. The low-frequency octupole excitations are also investigated and the microscopic mechanism for the enhancement of transition strengths is discussed.

Accepted for publication in Eur. Phys. J. A, as a contribution to the ENAM08 conference

References in corpus (8)

• Exotic modes of excitation in atomic nuclei far from stability
• Finite amplitude method for the RPA solution
• Role of deformation on giant resonances within the QRPA approach and the Gogny force
• Deformed quasiparticle-random-phase approximation for neutron-rich nuclei using the Skyrme energy density functional
• Mixed Representation RPA Calculation for Octupole Excitations on Superdeformed Sates in the 40Ca and Neutron-Rich Sulfur Regions
• Pairing and continuum effects on low-frequency quadrupole vibrations in deformed Mg isotopes close to the neutron drip line
• Low-frequency $K^{\pi }=0^{+}$ modes in deformed neutron-rich nuclei: Pairing- and $\beta$-vibrational modes of neutron
• Gamow-Teller strength distributions in Xe isotopes

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• Shape evolution of giant resonances in Nd and Sm isotopes
• Hartree-Fock-Bogoliubov theory for odd-mass nuclei with a time-odd constraint and application to deformed halo nuclei
• The nuclear energy density functional formalism
• Charge-exchange dipole excitations in deformed nuclei
• Triaxial-shape dynamics in the low-lying excited $0^{+}$ state: Role of the collective mass
• Pairing and nonaxial-shape correlations in $N=150$ isotones
• Cranked Skyrme-Hartree-Fock-Bogoliubov approach for a mean-field description of nuclear rotations near the drip line
• Enhanced moments of inertia for rotation in neutron-rich nuclei
• Isovector giant monopole and quadrupole resonances in a Skyrme energy density functional approach with axial symmetry