Quadrupole collectivity and shell closure in neutron-rich nuclei around $N=126$

Abstract

We present a comprehensive study on the low-lying states of neutron-rich Er, Yb, Hf, and W isotopes across the $N=126$ shell with a multi-reference covariant density functional theory. Beyond mean-field effects from shape mixing and symmetry restoration on the observables that are relevant for understanding quadrupole collectivity and underlying shell structure are investigated. The general features of low-lying states in closed-shell nuclei are retained in these four isotopes around $N=126$, even though the shell gap is overall quenched by about 30\% with the beyond mean-field effects. These effects are consistent with the previous generator-coordinate calculations based on Gogny forces, but much smaller than that predicted by the collective Hamiltonian calculation. It implies that the beyond mean-field effects on the $r$-process abundances before the third peak at $A\sim 195$ might be more moderate than that found in A. Arcones and G. F. Bertsch, Phys. Rev. Lett. 108, 151101 (2012).

12 pages with 13 figures and 1 table

References in corpus (16)

• Relativistic Continuum Hartree Bogoliubov Theory for Ground State Properties of Exotic Nuclei
• The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries
• New parametrization for the nuclear covariant energy density functional with point-coupling interaction
• Surface diffuseness correction in global mass formula
• Relativistic Nuclear Energy Density Functionals: adjusting parameters to binding energies
• Global performance of covariant energy density functionals: ground state observables of even-even nuclei and the estimate of theoretical uncertainties
• The limits of the nuclear landscape explored by the relativistic continuum Hatree-Bogoliubov theory
• Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. IX: Constraint of pairing force to ${}^1{S}_0$ neutron-matter gap
• Dynamical r-process studies within the neutrino-driven wind scenario and its sensitivity to the nuclear physics input
• The sign of the overlap of HFB wave functions
• A microscopic benchmark-study of triaxiality in low-lying states of 76Kr
• Covariant energy density functionals: nuclear matter constraints and global ground state properties
• Global study of beyond-mean-field correlation energies in covariant energy density functional theory using a collective Hamiltonian method
• Collectivity-induced quenching of signatures for shell closures
• Toward global beyond-mean-field calculations of nuclear masses and low-energy spectra
• Beyond mean-field study of elastic and inelastic electron scattering off nuclei

Cited by in corpus (3)

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