Theoretical Studies Of The Decay Properties Of Heavy And Superheavy Nuclei

With the continuous development of nuclear physics for more than 100 years,people have gained a deeper understanding of stable or relatively longlived nuclides.The properties of nuclides in the extreme regions of the nuclide diagram have become a hot spot and a focus of nuclear physics research.In this paper,the decay properties of nuclides in the two extreme regions of the nuclide diagram are investigated: in the first work,the proton radioactivity of the proton-rich nuclei in the medium-heavy region is studied,while in the second work,the decay properties of the Z=114 isotopic chain and the N=184 isotonic chain in the super-heavy region are explored,including the location and properties of the stable islands of super-heavy nuclei.The paper is therefore divided into two parts as follows.1: The proton radioactive half-lives of nuclei in the heavy nucleus region in 69≤Z≤83 have been studied based on the Generalized Droplet Model(GLDM).The proximity potential Prox.77-13 best describes the experimental data of proton radioactive half-lives of 27 spherical proton emitters when applied selfconsistently to the 16 proximity potentials in the GLDM.Combined with the fact that the proximity potential is also known to best describe the α decay under GLDM,this suggests that the proximity potential is more suitable for decay calculations under GLDM.Further,the proximity potential Prox.77-13 is used in GLDM to predict the proton radioactive half-life of the 14 spherical proton emitters.Finally,the Geiger-Nuttall law for proton radioactivity is investigated,revealing that for nuclides in the isotope chain,the results follow the law well as long as the emitted protons all carry the same angular momentum.It also shows that the introduction of the centrifugal potential under GLDM is important for the prediction of proton radioactivity.2: Many theories have predicted that the nuclide298 Fl is a spherical double magic nucleus and also the center of the stability island of super-heavy nuclei.In this work,based on the macroscopic-microscopic nuclear mass model(WS*),the binding energies of nuclides in the super-heavy nucleus region are calculated,and the single and double nucleon separation energies,α decay energies of Z=114 isotopic chains and N=184 isotonic isotopic chains are further calculated,which are combined with the available experimental data to explore the location of the stability island of super-heavy nuclei from the decay perspective;and the results are compared with those of the finite-range liquid-drop model(FRDM2012).Subsequently,the corresponding single-particle energy levels are calculated via the Woods-Saxon potential with spin-orbit terms,which can be used as a powerful tool to identify the presence of shell effects in298 Fl.The macroscopic properties and the microscopic physical information obtained from these calculations give an important signal at the same time that298 Fl is most likely a spherical double magic nucleus and the center of the stability island of super-heavy nuclei.