Shape coexistence in very neutron-deficient Pt isotopes

Dracoulis, George; Stuchbery, A.E.; Byrne, Aidan; Poletti, A.R.; Poletti, S.J.; Gerl, J.; Bark, R. A.

doi:10.1088/0305-4616/12/3/005

Cited by 139 publications

(70 citation statements)

References 19 publications

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“…Early calculations by Kumar and Baranger that were quite consistent with the data [61] indicated a change from a prolate towards a more oblate ground-state shape between A = 188 and A = 190 and were later substantiated by studies from Bengtsson et al [62]. Stuchbery et al [20] analysed gyromagnetic factors starting from the two-band mixing study carried out by Dracoulis et al [63], in which the mixing between a regular and an intruder configuration consistent with the measured B(E2) and with E0 measurements by Xu et al [64] was extracted. The calculations by Stuchbery et al [20] pointed out that the data cannot be described using only a single configuration but are consistent with the mixing of two configurations.…”

Section: A Gyromagnetic Factorsmentioning

confidence: 80%

Platinum nuclei: Concealed configuration mixing and shape coexistence

2011

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The role of configuration mixing in the Pt region is investigated. For this chain of isotopes, the nature of the ground state changes smoothly, being spherical around mass A ∼ 174 and A ∼ 192 and deformed around the mid-shell N = 104 region. This has a dramatic effect on the systematics of the energy spectra as compared to the systematics in the Pb and Hg nuclei. Interacting Boson Model with configuration mixing calculations are presented for gyromagnetic factors, α-decay hindrance factors, and isotope shifts. The necessity of incorporating intruder configurations to obtain an accurate description of the latter properties becomes evident.PACS numbers: 21.10.-k, 21.60.-n, 21.60.Fw.

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Section: A Gyromagnetic Factorsmentioning

confidence: 80%

Platinum nuclei: Concealed configuration mixing and shape coexistence

2011

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“…Experimentally, low-lying spectroscopy provides a very powerful source of information that allows one to establish signatures correlating the nuclear shape evolution with the energy spectra [14][15][16][17][18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Collective structural evolution in neutron-rich Yb, Hf, W, Os, and Pt isotopes

et al. 2011

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An interacting-boson-model Hamiltonian determined from Hartree-Fock-Bogoliubov calculations with the microscopic Gogny energy density functional D1M is applied to the spectroscopic analysis of neutron-rich Yb, Hf, W, Os, and Pt isotopes with mass A ∼ 180-200. Excitation energies and transition rates for the relevant low-lying quadrupole collective states are calculated by this method. Transitions from prolate to oblate ground-state shapes are analyzed as a function of neutron number N in a given isotopic chain by calculating excitation energies, B(E2) ratios, and correlation energies in the ground state. It is shown that such transitions tend to occur more rapidly for the isotopes with lower proton number Z when departing from the proton shell closure Z = 82. The triaxial degrees of freedom turn out to play an important role in describing the considered mass region. Predicted low-lying spectra for the neutron-rich exotic Hf and Yb isotopes are presented. The approximations used in the model and the possibilities to refine its predictive power are addressed.

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“…Nevertheless, a fully microscopic understanding of the evolution of the nuclear shapes with the number of nucleons still remains a major challenge [5][6][7][8][9][10][11][12][13][14]. From the experimental point of view, low-lying spectroscopy is one of the most powerful sources of information about structural evolution and/or shape transitions in atomic nuclei because it allows us to establish signatures correlating the excitation energies with deformation properties [15][16][17][18][19][20][21]. In particular, the complex interplay between several deformation degrees of freedom, taking place in different regions of the nuclear chart, offers the possibility of testing microscopic descriptions of atomic nuclei under a wide variety of conditions.…”

Section: Introductionmentioning

confidence: 99%

Structural evolution in Pt isotopes with the interacting boson model Hamiltonian derived from the Gogny energy density functional

et al. 2011

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Spectroscopic calculations are carried out for the description of the shape/phase transition in Pt nuclei in terms of the interacting boson model (IBM) Hamiltonian derived from (constrained) Hartree-Fock-Bogoliubov (HFB) calculations with the finite range and density-dependent Gogny-D1S energy density functional. Assuming that the many-nucleon driven dynamics of nuclear surface deformation can be simulated by effective bosonic degrees of freedom, the Gogny-D1S potential energy surface (PES) with quadrupole degrees of freedom is mapped onto the corresponding PES of the IBM. By using this mapping procedure, the parameters of the IBM Hamiltonian, relevant to the low-lying quadrupole collective states, are derived as functions of the number of valence nucleons. Merits of both Gogny-HFB and IBM approaches are utilized so that the spectra and the wave functions in the laboratory system are calculated precisely. The experimental low-lying spectra of both ground-state and sideband levels are well reproduced. From the systematics of the calculated spectra and the reduced E2 transition probabilities B(E2), the prolate-to-oblate shape/phase transition is shown to take place quite smoothly as a function of neutron number N in the considered Pt isotopic chain, for which the γ softness plays an essential role. All of these spectroscopic observables behave consistently with the relevant PES and the derived parameters of the IBM Hamiltonian as functions of N . Spectroscopic predictions are also made for those nuclei that do not have enough experimental E2 data.

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Shape coexistence in very neutron-deficient Pt isotopes

Cited by 139 publications

References 19 publications

Platinum nuclei: Concealed configuration mixing and shape coexistence

Platinum nuclei: Concealed configuration mixing and shape coexistence

Collective structural evolution in neutron-rich Yb, Hf, W, Os, and Pt isotopes

Structural evolution in Pt isotopes with the interacting boson model Hamiltonian derived from the Gogny energy density functional

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