α Decay Properties of Even-Even Nuclei296-308120 Within the Two-Potential Approach

In the present work,we predict the α decay half-lives of unknown even-even nuclei 296-308120 within the two-potential approach,whose α decay energy Qa is calculated using WS3+mass model.To reduce the deviations between the predictions and experimental data due to nuclear shell effect,the analytic formula of α decay hindrance factor is introduced to the two-potential approach,whose parameters had been extracted from even-even nuclei in the region of 82 <Z <126 and 152 <N ≤184 in our previous work [Deng et al.,Chin.Phys.C 42(2018) 044102].In addition,for comparing,we use a type of α decay general formula Universal Decay Law(UDL) and a semi-empirical formula in the superheavy nucleus(SEMFLS) to calculate the half-lives of even-even nuclei 296-308120.The results indicate that our predicted values and the calculated values of the above two empirical formulas are mutually confirmed.Meanwhile,we systematically study α decay chains of 296-308120 and predict the decay modes for superheavy nuclei to help to identify new superheavy isotopes.

Systematic study of α decay half-lives for even–even nuclei within a deformed two-potential approach

In this work,we systematically study theαdecay half-lives of 196 even–even nuclei using a two-potential approach improved by considering nuclear deformation.The results show that the accuracy of this model has been improved after considering nuclear deformation.In addition,we extend this model to predict theαdecay half-lives of Z=118 and 120 isotopes by inputting theαdecay energies extracted from the Weizsacker–Skyrme-type(WS-type)mass model,a simple nuclear mass formula,relativistic continuum Hartree–Bogoliubov theory and Duflo-Zuker-19(DZ19)mass model.It is useful for identifying the new superheavy elements or isotopes for future experiments.Finally,the predictedαdecay energies and half-lives of Z=118 and 120isotopes are analyzed,and the shell structure of superheavy nuclei is discussed.It shows that the shell effect is obvious at N=184,while the shell effect at N=178 depends on the nuclear mass model.

α decay properties of ^(296)Og within the two-potential approach

The present work is a continuation of our previous paper[J.-G. Deng, et al., Chin. Phys. C, 41：124109 （2017）]. In the present work, the α decay half-life of the unknown nucleus 296Og is predicted within the two-potential approach and the hindrance factors of all 20 even-even nuclei in the same region as 296Og, i.e. proton number 82 〈 Z 〈 126 and neutron number 152 〈 N 〈 184, from 250Cm to 294Og, are extracted. The prediction is 1.09 ms within a factor of 5.12. In addition, based on the latest experimental data, a new set of parameters of α decay hindrance factors for the even-even nuclei in this region, considering the shell effect and proton-neutron interaction, are obtained.

Systematic study of two-proton radioactivity half-lives using the two-potential and Skyrme-Hartree-Fock approaches

In this work,we systematically study the two-proton(2_(p))radioactivity half-lives using the two-potential approach,and the nuclear potential is obtained using the Skyrme-Hartree-Fock approach and the Skyrme effective interaction of SLy8.For true 2_(p) radioactivity(Q2_(p)>0 and Q_(p)<0,where Q_(p) and Q2_(p) are the released energies of the one-proton and two-proton radioactivity,respectively),the standard deviation between the experimental half-lives and our theoretical calculations is 0.701.In addition,we extend this model to predict the half-lives of 15 possible 2_(p) radioactivity candidates with Q2_(p)>0 obtained from the evaluated atomic mass table AME2016.The calcu-lated results indicate a clear linear relationship between the logarithmic 2_(p) radioactivity half-lives(logio10T_(1/2))and coulomb parameters[(Z_(d)^(0.8)+l^(0.25))Q_(2_(p))^(-1/2)]considering the effect of orbital angular momentum proposed by Liu et al.[Chin.Phys.C 45,024108(2021)].For comparison,the generalized liquid drop model(GLDM),effective liquid drop model(ELDM),and Gamow-like model are also used.Our predicted results are consistent with those obtained using other relevant models.

α decay properties of 297Og within the two-potential approach

The α decay half-life of the unknown nucleus 297Og is predicted within the two-potential approach, andα preformation probabilities of 64 odd-A nuclei in the region of proton numbers 82 〈 Z 〈 126 and neutron numbers 152 〈 N 〈 184, from 251Cf to 295Og, are extracted. In addition, based on the latest experimental data, a new set of parameters for α preformation probabilities considering the shell effect and proton-neutron interaction are obtained.The predicted α decay half-life of 297Og is 0.16 ms within a factor of 4.97. The predicted spin and parity of the ground states for 269Sg,285Fl and 293Lv are 3/2＋, 3/2＋ and 5/2＋, respectively.

Systematic study on the proton radioactivity of spherical proton emitters

In this study, based on a two-potential approach, we systematically investigated the proton radioactivity half-lives of spherical proton emitters with 69≤Z≤81 from the ground and/or isomeric state, choosing the nuclear potential to be a modified Woods–Saxon potential that contains the isospin effect of the daughter nucleus. It was found that the calculated half-lives could reproduce the experimental data well. Furthermore, we extended this model to predict the half-lives of 17 protonemitting candidates whose radioactivity is energetically allowed or observed but not yet quantified in NUBASE2020. For comparison, the unified fission model, Coulomb potential and proximity potential model, universal decay law for proton emission, and new Geiger–Nuttall law were also used. All the predicted results are consistent with each other.

Systematic study of α preformation probability of nuclear isomeric and ground states

In this paper, based on the two-potential approach combining with the isospin dependent nuclear potential, we systematically compare the α preformation probabilities of odd-A nuclei between nuclear isomeric states and ground states. The results indicate that during the process of α particle preforming, the low lying nuclear isomeric states are similar to ground states. Meanwhile, in the framework of single nucleon energy level structure, we find that for nuclei with nucleon number below the magic numbers, the α preformation probabilities of high-spin states seem to be larger than low ones. For nuclei with nucleon number above the magic numbers, the α preformation probabilities of isomeric states are larger than those of ground states.