Shape mixing dynamics in the low-lying states of proton-rich Kr isotopes

Abstract

We study the oblate-prolate shape mixing in the low-lying states of protonrich Kr isotopes using the five-dimensional quadrupole collective Hamiltonian. The collective Hamiltonian is derived microscopically by means of the CHFB (constrained Hartree-Fock-Bogoliubov) + Local QRPA (quasiparticle random phase approximation) method, which we have developed recently on the basis of the adiabatic self-consistent collective coordinate method. The results of the numerical calculation show the importance of large-amplitude collective vibrations in the triaxial shape degree of freedom and rotational effects on the oblate-prolate shape mixing dynamics in the low-lying states of these isotopes.

Shape coexistence and evolution in neutron-deficient krypton isotopes

“…In particular, a quadrupole deformation of |β 2 | = 0.330 (21) [11]. This value, though ambiguous by itself, yet in comparison with the predictions of a variety of self-consistent models, points to an oblate character of the ground state of 72 Kr [11].…”

Triaxial quadrupole deformation dynamics insd-shell nuclei aroundMg26

“…A new point of this method is that the contributions from the time-odd mean field are taken into account in evaluating the vibrational and rotational inertial masses. So far this CHFB + LQRPA method in conjunction with the pairing-plus-quadrupole (P+Q) model [29,30] including the quadrupole-pairing force has been successfully applied to the oblate-prolate shape coexistence in proton-rich Se and Kr isotopes [28,31].…”

Microscopic derivation of the quadrupole collective Hamiltonian for shape coexistence/mixing dynamics

“…Then, a practical approximation scheme, called local QRPA (LQRPA) method, has been developed [41,42,43]. This scheme may be regarded as a first step of iterative solution of Eqs.…”

“…The single-particle energies and the P+Q interaction strengths are determined such that the results of the Skyrme-HFB calculation for the ground states are best reproduced within the P+Q model (see Refs. [42,49] for details). The LQRPA method is quite general and it can be used in conjunction with various Skyrme interactions or modern density functionals.…”

“…A step toward this goal has recently been carried out for axially symmetric cases [50]. More examples can be found in [51] 72 Kr by means of the CHB+LQRPA method (denoted by LQRPA) [42] and experimental data [54,55]. For comparison, the results calculated using the Inglis-Belyaev cranking mass are also shown.…”