https://doi.org/10.1140/epja/i2008-10742-y
Regular Article - Theoretical Physics
Skyrme-QRPA calculations for low-lying excitation modes in deformed neutron-rich nuclei
Nishina Center for Accelerator-Based Science, RIKEN, 351-0198, Wako, Saitama, Japan
* e-mail: Kenichi.Yoshida@riken.jp
Received:
8
December
2008
Revised:
13
January
2009
Accepted:
6
February
2009
Published online:
17
March
2009
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 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 34Mg and 40Mg is acquired due to the coherent coupling between the
vibration and the pairing vibration of neutrons. Microscopic structure of the
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
-vibrational mode in 24Mg continues to play a key role in the near-drip-line nucleus 40Mg . The low-frequency octupole excitations are also investigated and the microscopic mechanism for the enhancement of transition strengths is discussed.
© SIF, Springer-Verlag Berlin Heidelberg, 2009