Bubble structure in superheavy nuclei around neutron and proton shell closure

Author(s):  
Akhilesh Yadav ◽  
A. Shukla ◽  
Sven Åberg

We have performed a systematic study for the nuclear structure of superheavy nuclei with a special emphasis on the nuclei with possible central depletion of proton and neutron density in the mass region [Formula: see text] using the Relativistic Hartree–Bogoliubov (RHB) framework. It has been observed that in the case of neutron density distribution, the occurrence of central depletion is related to the occupancy of 4s orbital and it is found to decrease with increasing occupancy of the 4s orbital. On the other hand, in the case of proton density distribution, the central density depletion is mainly due to the lowering of weakly bound p-orbital states close to the continuum as it is energetically favored to lower the Coulomb repulsion in the case of superheavy nuclei. Also, occupation probability of the lower angular momentum states (p-orbitals) lying near the Fermi level is strongly suppressed due to the weak centrifugal barrier and strong Coulomb repulsion in comparison to large angular momentum states (contributing to surface region mainly), resulting in central density depletion. Among the considered cases in the present work, the maximum depletion is observed for [Formula: see text] and for [Formula: see text]Og under spherically symmetric and axially deformed cases, respectively.

2020 ◽  
Vol 29 (08) ◽  
pp. 2050068
Author(s):  
M. Kumawat ◽  
G. Saxena ◽  
M. Kaushik ◽  
S. K. Jain ◽  
J. K. Deegwal ◽  
...  

In this work, we identify a unique and novel feature of central density depletion in both proton and neutron named as doubly bubble nuclei in [Formula: see text] region. The major role of 2d-3s single-particle (s.p.) states in the existence of halo and bubble nuclei is probed. The occupancy in s.p. state 3s[Formula: see text] leads to the extended neutron density distribution or halo while the unoccupancy results in the central density depletion. By employing the Relativistic Mean-Field (RMF) approach along with NL3* parameter, the separation energies, s.p. energies, pairing energies, proton and neutron density profiles along with deformations of even–even nuclei are investigated. Our results are concise with few other theories and available experimental data. Emergence on new shell closure and the magicity of conventional shell closures are explored systematically in this yet unknown region.


2021 ◽  
Vol 34 (1) ◽  
pp. 54-60
Author(s):  
J. J. Bevelacqua

Binding energies of nuclei are calculated in the mass region 1300 ≤ A < 1400. The calculations are performed using the adjusted Rost interaction, which suggests that a new island of stability exists for Z = 382 and in neighboring systems. Enhanced stability occurs in the <mml:math display="inline"> <mml:mrow> <mml:msubsup> <mml:mrow/> <mml:mn mathvariant="bold"> 382</mml:mn> <mml:mn mathvariant="bold">1344</mml:mn> </mml:msubsup> <mml:msub> <mml:mi mathvariant="bold">X</mml:mi> <mml:mrow> <mml:mn mathvariant="bold">962</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> system.


2006 ◽  
Vol 15 (07) ◽  
pp. 1587-1599 ◽  
Author(s):  
ZHONGZHOU REN ◽  
DINGHAN CHEN ◽  
CHANG XU

Superheavy elements have provided a good test of the validity of both nuclear structure models and nuclear decay models in a large mass region. We firstly review the recent progress on theoretical studies of superheavy nuclei. Emphasis is placed on the structure and decay of superheavy nuclei. Then theoretical results of odd-odd nuclei with Z = 109 - 115 are presented and discussed. It is clearly demonstrated that there is shape coexistence for the ground state of many superheavy nuclei from different models and many superheavy nuclei are deformed. In some cases superdeformation can become the ground state of superheavy nuclei and it is important for future studies of superheavy nuclei. This can lead to the existence of low-energy isomers in the superheavy region and it plays an important role for the stability of superheavy nuclei. As α-decay and spontaneous fission plays a crucial role for identifications of new elements, we also review some typical models of α-decay half-lives and spontaneous fissions half-lives. Some new views on superheavy nuclei are presented.


2012 ◽  
Vol 52 (6) ◽  
pp. 725-729 ◽  
Author(s):  
M. I. Verigin ◽  
G. A. Kotova ◽  
V. V. Bezrukikh ◽  
O. S. Aken’tieva

2020 ◽  
Vol 33 (3) ◽  
pp. 276-282
Author(s):  
J. J. Bevelacqua

Binding energies of nuclei are calculated in the mass region 1200 ≤ A < 1300. The calculations are performed using the adjusted Rost interaction, which suggests that a new island of stability exists for Z = 354 and neighboring systems. Enhanced stability occurs in the <mml:math display="inline"> <mml:mrow> <mml:mmultiscripts> <mml:mi mathvariant="bold">X</mml:mi> <mml:mprescripts/> <mml:mrow> <mml:mn> </mml:mn> <mml:mn>354</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>1226</mml:mn> </mml:mrow> </mml:mmultiscripts> <mml:msub> <mml:mrow/> <mml:mn>872</mml:mn> </mml:msub> </mml:mrow> </mml:math> system.


2020 ◽  
Vol 29 (09) ◽  
pp. 2050070
Author(s):  
S. Nejati ◽  
O. N. Ghodsi

In this study, the effect of the surface symmetry energy on the neutron skin thickness and division of it into the bulk and surface parts are investigated by determination of the symmetry energy coefficient [Formula: see text] of finite nuclei. We demonstrate the importance of the isospin asymmetry distribution in the symmetry energy coefficient of finite nuclei at the surface region. We attempt to find out how different surface symmetry energies may affect alpha decay half-life. The Skyrme interactions are used to describe the neutron and proton density distributions and to calculate the symmetry energy coefficient [Formula: see text] of four nuclei and the surface symmetry energy. The chosen Skyrme interactions can produce the binding energy and root-mean-square charge radii of both mother and daughter nuclei. We single out the spherical isotones of [Formula: see text] named [Formula: see text]Pb, [Formula: see text]Po, [Formula: see text]Rn and [Formula: see text]Ra for daughter nuclei and explore the dependence of the bulk and surface contributions on the surface symmetry energy. The half-life of mother nuclei, i.e., [Formula: see text]Po, [Formula: see text]Rn, [Formula: see text]Ra and [Formula: see text]Th, is employed to investigate the extent to which it is affected by different surface symmetry energies. The calculated half-lives show a downward tendency for different surface symmetry energies which can be caused by various neutron skin thicknesses.


2020 ◽  
Vol 29 (09) ◽  
pp. 2050073
Author(s):  
Sven Åberg ◽  
Akhilesh Yadav ◽  
A. Shukla

Experimental observation of [Formula: see text]Si as a proton bubble nuclei has heated up the interest in the study of exotic bubble shaped nuclei. In this work, some of the potential doubly bubble-like (for proton as well as neutron both simultaneously) cases have been explored using relativistic Hartree–Bogoliubov (RHB) in light mass region, specially around N or [Formula: see text]. Further, the role of pairing and the evolution of new shell gaps around [Formula: see text] or [Formula: see text] and 34 have been investigated, as one moves toward drip lines. This study suggests that the occupancies/vacancies of neutron/proton orbitals for lower angular momentum state plays major role in nuclear structure to create bubble-like structure and [Formula: see text]O[Formula: see text], [Formula: see text]Mg8 and [Formula: see text]Si[Formula: see text] may have dual bubble-like structures.


2018 ◽  
Vol 178 ◽  
pp. 02024
Author(s):  
Xiao-Tao He

The high-K isomeric states in light superheavy nuclei around A = 250 mass region are investigated by the Cranked Shell Model (CSM) with pairing treated by a Particle-Number Conserving (PNC) method. With including the higher-order deformation ε6, both of the high–K multi-particle state energies and the rotational bands in 254No and N = 150 isotone are reproduced well. The isomeric state energies and the microscopic mechanism of kinematic moment of inertia variations versus rotational frequency are discussed. The irregularity of the two-neutron Kπ = 8- state band at ħω ≈ 0:17 in 252No is caused by the configuration mixing with the two-proton Kπ = 8- band. .


Sign in / Sign up

Export Citation Format

Share Document