Shell structure and shape transition in odd-$Z$ superheavy nuclei with proton numbers $Z=117,119$: insights from deformed relativistic Hartree-Bogoliubov in continuum

Abstract

We present a systematic study on the structural properties of odd-$Z$ superheavy nuclei with proton numbers $Z=117,119$, and neutron numbers $N$ increasing from $N=170$ to the neutron dripline within the framework of axially deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc). The results are compared with those of even-even superheavy nuclei with proton numbers $Z=118$ and $120$. We analyze various bulk properties of their ground states, including binding energies, quadrupole deformations, root-mean-square radii, nucleon separation energies, and $\alpha$-decay energies. The coexistence of competing prolate and oblate or spherical shapes leads to abrupt changes in both quadrupole deformations and charge radii as functions of neutron numbers. Compared to even-even nuclei, the odd-mass ones exhibit a more complicated transition picture, in which the quantum numbers of $K^{\pi }$ of the lowest-energy configuration may change with deformation. This may result in the change of angular momentum in the ground-state to ground-state $\alpha$-decay and thus quench the decay rate in odd-mass nuclei. Moreover, our results demonstrate a pronounced proton shell gap at $Z=120$, instead of $Z=114$, which is consistent with the predictions of most covariant density functional theories. Moreover, large neutron shell gaps are found at $N=172$ and $N=258$ in the four isotopic chains, as well as at $N=184$ in the light two isotopic chains with $Z=117$ and $Z=118$, attributed to the nearly-degenerate $3d$ and $4p$ spin-orbit doublet states due to the presence of bubble structure.

15 pages with 18 figures

References in corpus (29)

• Relativistic Continuum Hartree Bogoliubov Theory for Ground State Properties of Exotic Nuclei
• New parametrization for the nuclear covariant energy density functional with point-coupling interaction
• Surface diffuseness correction in global mass formula
• Evolution of shell structure in exotic nuclei
• Neutron halo in deformed nuclei
• The limits of the nuclear landscape explored by the relativistic continuum Hatree-Bogoliubov theory
• Spherical Relativistic Hartree theory in a Woods-Saxon basis
• Deformed relativistic Hartree Bogoliubov theory in continuum
• Magic numbers for superheavy nuclei in relativistic continuum Hartree-Bogoliubov theory
• Cranked Relativistic Hartree-Bogoliubov Theory: probing the gateway to superheavy nuclei
• Deformed relativistic Hartree-Bogoliubov theory in continuum with point coupling functional: examples of even-even Nd isotopes
• Covariant density functional theory: Reexamining the structure of superheavy nuclei
• Properties of heaviest nuclei with $98\le Z\le 126$ and $134\le N\le 192$
• Superheavy magic structures in the relativistic Hartree-Fock-Bogoliubov approach
• Nuclear mass table in deformed relativistic Hartree-Bogoliubov theory in continuum, II: Even-$Z$ nuclei
• Systematics of low-lying states of even-even nuclei in the neutron-deficient lead region from a beyond-mean-field calculation
• Relativistic Energy Density Functional Description of Shape Transition in Superheavy Nuclei
• Predictive power for superheavy nuclear mass and possible stability beyond the neutron drip line in deformed relativistic Hartree-Bogoliubov theory in continuum
• Odd systems in deformed relativistic Hartree Bogoliubov theory in continuum
• Deformed relativistic Hartree-Bogoliubov theory in continuum with a point-coupling functional. II. Examples of odd Nd isotopes
• Density-dependent deformed relativistic Hartree-Bogoliubov theory in continuum
• Hyperheavy nuclei: existence and stability
• Extension of nuclear landscape to hyperheavy nuclei
• Optimized Dirac Woods-Saxon basis for covariant density functional theory
• Microscopic calculations of weak decays in superheavy nuclei
• Hyperheavy spherical and toroidal nuclei: the role of shell structure
• Microscopic Calculation of Fission Product Yields for Odd-Mass Nuclei
• Multireference covariant density-functional theory for the low-lying states of odd-mass nuclei
• Quadrupole collectivity and shell closure in neutron-rich nuclei around $N=126$

Cited by in corpus (2)

• Triaxial relativistic Hartree-Bogoliubov theory in continuum for exotic nuclei
• Ground-state properties and structure evolutions of odd-$A$ transuranium Bk isotopes from deformed relativistic Hartree-Bogoliubov theory in continuum