REVIEW ON THEORETICAL STUDIES OF SUPERHEAVY NUCLEI

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.

2013 ◽  
Vol 22 (01) ◽  
pp. 1350001 ◽  
Author(s):  
S. K. SINGH ◽  
M. IKRAM ◽  
S. K. PATRA

We calculate the ground state properties of recently synthesized superheavy elements (SHEs) from Z = 105–118 along with the predicted proton magic Z = 120. The relativistic and nonrelativistic mean field formalisms are used to evaluate the binding energy (BE), charge radius, quadrupole deformation parameter and the density distribution of nucleons. We analyzed the stability of the nuclei based on BE and neutron to proton ratio. We also studied the bubble structure which reveals the special features of the superheavy nuclei.


1971 ◽  
Vol 26 (4) ◽  
pp. 643-652 ◽  
Author(s):  
Jens Grumann ◽  
Tihomir Morovic ◽  
Walter Greiner

AbstractThe potential energy surface has been calculated by two methods which are compared with re­spect to spontaneous fission. In the first one essentially the sum of the single particle energies is computed as was done in a previous paper3 while in the second one the Strutinsky technique of renormalizing to a liquid drop model has been applied. Also the half-lives for electron capture are investigated together with the predictions of the half-lives for spontaneous fission and α-decay. The results support the existence of superheavy nuclei in the regions around Z = 114 and Z = 164.


2008 ◽  
Vol 17 (07) ◽  
pp. 1309-1317
Author(s):  
FANG ZHOU ◽  
JIAN-YOU GUO

The superheavy nucleus 294118 and its α-decay chain have been investigated systematically in the relativistic mean-field (RMF) theory with the interactions NL3, TMA, PK1 and NLZ. The properties of ground state have been described well with the binding energies per nucleon and α-decay energies, which are reproduced as compared with the experimental data. It shows that the RMF theory is effective for studying not only the stable nuclei but also the superheavy nuclei presented here. In particular, the prolate shape predicted in the ground state of these superheavy nuclei is in agreement with the experimental data as well as other theoretical calculations.


1970 ◽  
Vol 140 (2) ◽  
pp. 289-304 ◽  
Author(s):  
Chin Fu Tsang ◽  
Sven Gösta Nilsson

2008 ◽  
Vol 17 (09) ◽  
pp. 1945-1954
Author(s):  
ZHONGZHOU REN ◽  
DINGHAN CHEN ◽  
YUQING CHEN ◽  
CHANG XU

We have investigated the ground-state properties of odd-Z superheavy isotopes with even neutron numbers in previous article (Phys. Rev. C67 064302 (2003)). In this work we extend the previous researches to the ground-state properties of odd-Z isotopic chains with odd neutron numbers. This covers the isotopic chains with Z = 109 - 115 which are current interests of experiments. The ground state properties of these odd-Z superheavy nuclei have been systematically calculated by deformed relativistic mean-field model (RMF) with two sets of force parameters TMA and NL-Z2. The theoretical results from the RMF model are compared with those from the Skyrme-Hartree-Fock model (SHF). The binding energies of two models are in good agreement with each other, but the quadrupole deformations show model dependence in some mass regions. The alpha decay energies from the two theoretical models are also compared with recent experimental data, which include three alpha decay chains of superheavy elements 115 and 113. The reasonable agreement shows the validity of the self-consistent mean-field models for superheavy mass region.


2021 ◽  
Vol 256 ◽  
pp. 00010
Author(s):  
Mihail Mirea

The fine structure of α-decay is treated with fission-like models. The single particle levels are calculated along a least action path connecting the ground state of the parent nucleus and the configuration of two spherical tangent nuclei. The probabilities to find different seniority-1 configurations are obtaining by solving the time-dependent pairing equations generalized by including the Landau-Zener effect and the Coriolis coupling. The theoretical results for the α-decay of 211Po and 211Bi are compared with experimental data showing a good agreement.


1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.


2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Shuai Yang ◽  
Haijun Jiang ◽  
Cheng Hu ◽  
Juan Yu ◽  
Jiarong Li

Abstract In this paper, a novel rumor-spreading model is proposed under bilingual environment and heterogenous networks, which considers that exposures may be converted to spreaders or stiflers at a set rate. Firstly, the nonnegativity and boundedness of the solution for rumor-spreading model are proved by reductio ad absurdum. Secondly, both the basic reproduction number and the stability of the rumor-free equilibrium are systematically discussed. Whereafter, the global stability of rumor-prevailing equilibrium is explored by utilizing Lyapunov method and LaSalle’s invariance principle. Finally, the sensitivity analysis and the numerical simulation are respectively presented to analyze the impact of model parameters and illustrate the validity of theoretical results.


2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
N. H. Sweilam ◽  
S. M. Al-Mekhlafi ◽  
A. O. Albalawi ◽  
D. Baleanu

Abstract In this paper, a novel coronavirus (2019-nCov) mathematical model with modified parameters is presented. This model consists of six nonlinear fractional order differential equations. Optimal control of the suggested model is the main objective of this work. Two control variables are presented in this model to minimize the population number of infected and asymptotically infected people. Necessary optimality conditions are derived. The Grünwald–Letnikov nonstandard weighted average finite difference method is constructed for simulating the proposed optimal control system. The stability of the proposed method is proved. In order to validate the theoretical results, numerical simulations and comparative studies are given.


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