利用改进的Gamow-like模型研究原子核的α衰变和质子放射性

通过引入离心势和静电屏蔽效应对Gamow-like模型进行了改进，并将其用于α衰变和质子放射性研究，发现改进的Gamow-like模型能更好地符合实验数据。另外，还利用改进的Gamow-like模型预言了16个丰质子核的质子放射性的半衰期以及7个$Z=120$超重核素($^{296-308}120$)α衰变链上原子核的α衰变的半衰期，为将来在大科学装置上合成和鉴别这些新核素提供重要的理论参考。     

基于折叠势的两势方法系统研究质子放射性(英文)

基于两势方法系统地研究了质子数51 ≤ Z ≤ 83质子放射性核素的衰变半衰期。总的质子-子核相互作用势包括:通过单折叠子核密度和DDM3Y有效相互作用得到的微观核势,通过单折叠子核电荷密度和质子-质子库仑相互作用得到的真实库仑势以及离心势。同时,预测了同一区域16个核的质子放射性半衰期,并且预测的质子放射性半衰期在4.11倍的范围内。此外,还研究了质子放射性的Geiger-Nuttall定律。结果表明,Geiger-Nuttall定律可以用来描述角动量相同的同位素的质子放射性。In the present work, we systematically study the half-lives of proton radioactivity for 51 ≤ Z ≤ 83 nuclei within the two-potential approach. The total emitted proton-daughter nucleus interaction potential is composed of the microscopic nuclear potential obtained by single folding the density of the daughter nucleus with the DDM3Y effective interaction, the realistic Coulomb potential obtained by single folding the charge density of the daughter nucleus with the proton-proton Coulomb interaction and the centrifugal potential. We extend our study to predict proton radioactivity half-lives of 16 nuclei in the same region within a factor of 4.11. In addition, the Geiger-Nuttall law for proton radioactivity is researched. The results indicate that the Geiger-Nuttall law can be used to describe the proton radioactivity isotopes with same angular momentum.     

基于两势方法系统研究壳结构对原子核α衰变的影响

基于两势方法（two-potential-approach,TPA）系统研究了偶-偶核、奇-A核和奇-奇核α衰变半衰期。为了考虑原子核的壳结构的影响而导致的实验半衰期与计算结果之间的偏差,引入了与α结团形成概率相关的禁戒因子和预形成因子。结合前期相关工作[X.D.Sun et al.,Phys.Rev.C 93,034316（2016）;X.D.Sun et al.,Phys.Rev.C 95,014319（2017）;X.D.Sun et al.,Phys.Rev.C 95,044303（2017）],考虑到壳效应对α粒子预形成的影响,通过分析α衰变半衰期的实验数据,拟合得到了α粒子预形成因子/禁戒因子修正公式的参数,得到了α衰变预形成因子/禁戒因子的计算结果,证实了壳效应及质子-中子相互作用在α结团形成过程中起着重要的作用,离壳越近预形成概率越小离壳越远预形成概率越大。In the present work, the α decay half-lives are systematically studied within the two-potentialapproach for even-even nuclei, odd-A nuclei and odd-odd nuclei. To describe the deviations between experimental half-lives and calculated results due to the nuclear shell structure, α preformation factor and hindrance factor related with α cluster preformation probability are introduced. It is consistent with our previous works[X. D. Sun et al., Phys. Rev. C 93, 034316 (2016); X. D. Sun et al., Phys. Rev. C 95, 014319 (2017); X. D. Sun et al., Phys. Rev. C 95, 044303 (2017)]. Considering the shell effect on the preformation of α and by analyzing the experimental data of the α decay half-lives, the parameters of the α preformation factor/hindrance factor correction formula are obtained. we confirm that the shell effect and the proton-neutron correlation play key roles in the α preformation where the preformation probability near the shell is less than the preformation probability far from the shell.     

Systematic study of two-proton radioactivity within a Gamow-like model

In this study,based on the Gamow-like model,we systematically analyze two-proton(2p) radioactivity half-lives of nuclei near or beyond the proton drip line.It is found that the calculated results can reproduce experimental data well.Furthermore,using this model,we predict the half-lives of possible 2p radioactivity candidates whose 2p radioactivity is energetically allowed or observed but not yet quantified in the latest table of evaluated nuclear properties,i.e.,NUBASE2016.The predicted results are in good agreement with those from other theoretical models and empirical formulas,namely the effective liquid drop model(ELDM),generalized liquid drop model(GLDM),Sreej a formula,and Liu formula.     

基于结团形成模型系统研究Z=82,N=126闭壳附近原子核的α衰变

基于结团形成模型（cluster-formation model,CFM）系统地研究了质子数Z=82,中子数N=126闭壳附近的α衰变母核的α衰变预形成因子P_α。计算结果表明:基于结团形成模型计算得到的P_α线性地依赖于价质子（空穴）N_p和价中子（空穴）N_n的乘积。这与前期工作[SUN X D,et al.Phys Rev C,2016, 94 （2）:024338;DENG J G,et al.Phys Rev C,2017, 96 （2）:024318]得到的结论是一致的,其中,P_α是唯象的且模型依赖的,从α衰变半衰期的理论值和实验值的比值中提取。结合前期工作可以得到这样的结论:对于Z=82,N=126闭壳附近的α衰变母核,其P_α与N_pN_n呈线性关系,且价质子-价中子相互作用在α结团预形成中起了很重要的作用。In the present work, the α decay preformation factors P_α are systematically studied within the cluster-formation model (CFM) for nuclei around Z=82, N=126 closed shells. The calculations show that the P_α calculated by CFM is linearly dependent on the product of valance protons (holes) and valance neutrons (holes) N_p N_n. It is consistent with our previous works[SUN X D, et al. Phys Rev C, 2016, 94 (2):024338; DENG J G, et al. Phys Rev C, 2017, 96 (2):024318], which P_α are model-dependent and extracted from the ratios of calculated α decay half-lives to experimental data. Combining with our previous works, we confirm that the P_α is linearly dependent on the N_pN_n for nuclei around Z=82, N=126 shell closures. In addition, the valance proton-neutron interaction plays a key role in the α preformation.