Octupole correlations in collective excitations of neutron-rich $N\approx 56$ nuclei

Abstract

Octupole correlations in the low-energy collective states of neutron-rich nuclei with the neutron number $N\approx 56$ are studied within the interacting boson model (IBM) that is based on the nuclear density functional theory. The constrained self-consistent mean-field (SCMF) calculations using a universal energy density functional and a pairing interaction provide the potential energy surfaces in terms of the axially-symmetric quadrupole and octupole deformations for the even-even nuclei ${}^{86-94}$Se, ${}^{88-96}$Kr, ${}^{90-98}$Sr, ${}^{92-100}$Zr, and ${}^{94-102}$Mo. The SCMF energy surface is then mapped onto the energy expectation value of a version of the IBM in the boson condensate state, which consists of the neutron and proton monopole $s$, quadrupole $d$, and octupole $f$ bosons. This procedure determines the strength parameters of the IBM Hamiltonian, which is used to compute relevant spectroscopic properties. At the SCMF level, no octupole deformed ground state is obtained, while the energy surface is generally soft in the octupole deformation at $N\approx 56$. The predicted negative-parity yrast bands with the bandhead state $3_1^{-}$ weakly depend on $N$ and become lowest in energy at $N=56$ in each of the considered isotopic chains. The model further predicts finite electric octupole transition rates between the lowest negative- and the positive-parity ground-state bands.

arXiv comment19 pages, 13 figures, 4 tables

References in corpus (37)

• Relativistic Nuclear Energy Density Functionals: Mean-Field and Beyond
• Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies
• A finite range pairing force for density functional theory in superfluid nuclei
• DIRHB -- a relativistic self-consistent mean-field framework for atomic nuclei
• Quantum Phase Transition in the Shape of Zr isotopes
• Global systematics of octupole excitations in even-even nuclei
• Mean field and beyond description of nuclear structure with the Gogny force: A review
• Direct Evidence of Octupole Deformation in Neutron-Rich ${}^{144}$Ba
• Cluster Interpretation of Properties of Alternating Parity Bands in Heavy Nuclei
• Microscopic description of octupole shape-phase transitions in light actinides and rare-earth nuclei
• Direct Evidence for Octupole Deformation in ${}^{146}$Ba and the Origin of Large $E1$ Moment Variations in Reflection-Asymmetric Nuclei
• First Measurement of Collectivity of Coexisting Shapes based on Type II Shell Evolution: The Case of ${}^{96}$Zr
• Landscape of pear-shaped even-even nuclei
• Analytic Description of Critical Point Actinides in a Transition from Octupole Deformation to Octupole Vibrations
• Microscopic analysis of the octupole phase transition in Th isotopes
• Simultaneous quadrupole and octupole shape phase transitions in Thorium
• Spectroscopy of quadrupole and octupole states in rare-earth nuclei from a Gogny force
• Octupole deformation properties of the Barcelona-Catania-Paris energy density functionals
• Spectroscopy of reflection-asymmetric nuclei with relativistic energy density functionals
• First direct measurement of the intrinsic dipole moment in pear-shaped thorium isotopes
• Beyond relativistic mean-field approach for nuclear octupole excitations
• Octupole deformation in the nuclear chart based on the 3D Skyrme Hartree-Fock plus BCS model
• Quadrupole and octupole collectivity and cluster structures in neon isotopes
• Evidence for shape coexistence in ${}^{98}$Mo
• Octupole deformation in the ground states of even-even $Z\sim 96,N\sim 196$ actinides and superheavy nuclei
• Quadrupole and octupole softness in the N=Z nucleus 64Ge
• Parameter-Free Solution of the Bohr Hamiltonian for Actinides Critical in the Octupole Mode
• Octupole deformation in light actinides within an analytic quadrupole octupole axially symmetric model with Davidson potential
• Interrelation between the isoscalar octupole phonon and the proton-neutron mixed-symmetry quadrupole phonon in near spherical nuclei
• Evolution of octupole deformation and collectivity in neutron-rich lanthanides
• Octupole correlations in light actinides from the interacting boson model based on the Gogny energy density functional
• Quadrupole-octupole coupling and the onset of octupole deformation in actinides
• Microscopic description of octupole collective excitations near $N=56$ and $N=88$
• Microscopic description of quadrupole-octupole coupling in actinides with the Gogny-D1M energy density functional
• Quadrupole-octupole coupling and the evolution of collectivity in neutron-deficient Xe, Ba, Ce, and Nd isotopes
• Mixed-symmetry octupole and hexadecapole excitations in the N=52 isotones
• A solvable model for octupole phonons

Cited by in corpus (5)

• Mapped interacting boson model for nuclear structure studies
• Role of octupole shape degree of freedom in neutron-rich odd-mass xenon isotopes
• Quadrupole and octupole states in ${}^{152}$Sm using the proton-neutron interacting boson model
• Proton removal from ${}^{73,75}$Br to ${}^{72,74}$Se at intermediate energies
• Large scale shell model calculation for collectivity in nuclei beyond 78Ni