Shape coexistence revealed in the $N=Z$ isotope ${}^{72}$Kr through inelastic scattering

Abstract

The $N=Z=36$ nucleus ${}^{72}$Kr has been studied by inelastic scattering at intermediate energies. Two targets, ${}^9$Be and ${}^{197}$Au, were used to extract the nuclear deformation length, ${\delta }_{\text{N}}$, and the reduced $E2$ transition probability, $B(E2)$. The previously unknown non-yrast $2^{+}$ and $4^{+}$ states as well as a new candidate for the octupole $3^{-}$ state have been observed in the scattering on the Be target and placed in the level scheme based on $\gamma -\gamma$ coincidences. The second $2^{+}$ state was also observed in the scattering on the Au target and the $B(E2;2_2^{+}\to 0_1^{+})$ value could be determined for the first time. Analyzing the results in terms of a two-band mixing model shows clear evidence for a oblate-prolate shape coexistence and can be explained by a shape change from an oblate ground state to prolate deformed yrast band from the first $2^{+}$ state. This interpretation is corroborated by beyond mean field calculations using the Gogny D1S interaction.

arXiv comment12 pages, 11 figures, accepted European Physical Journal A

References in corpus (11)

• Toward a global description of the nucleus-nucleus interaction
• Structure of even-even nuclei using a mapped collective Hamiltonian and the D1S Gogny interaction
• Triaxial Angular Momentum Projection and Configuration Mixing calculations with the Gogny force
• Particle number projection with effective forces
• Overview of Neutron-Proton Pairing
• DALI2: A NaI(Tl) detector array for measurements of $\gamma$ rays from fast nuclei
• Shape coexistence in neutron-deficient Kr isotopes: Constraints on the single-particle spectrum of self-consistent mean-field models from collective excitations
• Beyond relativistic mean-field studies of low-lying states in neutron-deficient krypton isotopes
• Structure of Krypton isotopes calculated with symmetry conserving configuration mixing methods
• Global optical potential for nucleus-nucleus systems from 50 MeV/u to 400 MeV/u
• Shape mixing dynamics in the low-lying states of proton-rich Kr isotopes

Cited by in corpus (8)

• Shape coexistence in even-even nuclei: A theoretical overview
• Shape changes in the mirror nuclei ${}^{70}$Kr and ${}^{70}$Se
• Ab initio computations of strongly deformed nuclei around ${}^{80}$Zr
• Hexadecapole strength in the rare isotopes ${}^{74,76}$Kr
• Investigation of octupole collectivity near the $A=72$ shape-transitional point
• Improved measurement of the $0_2^{+}\to 0_1^{+}$ E0 transition strength for ${}^{72}$Se using the SPICE spectrometer
• Proton removal from ${}^{73,75}$Br to ${}^{72,74}$Se at intermediate energies
• Skyrme pseudopotentials at next-to-next-to-leading order Construction of local densities and first symmetry-breaking calculations