β-decay half-life is a key quantity for nuclear structure and nucleosynthesis studies.There exist large uncertainties in the contributions of allowed and forbidden transitions to the totalβ-decay life,which limits t...β-decay half-life is a key quantity for nuclear structure and nucleosynthesis studies.There exist large uncertainties in the contributions of allowed and forbidden transitions to the totalβ-decay life,which limits the resolution of the predictedβ-decay half-life.We systematically study the contribution of the first forbidden(FF)transitions to theβ--decay half-life,and quantify it with a formula based on simple physics considerations.We also propose a new formula for calculation of theβ--decay half-life that includes the FF contribution.It is shown that the inclusion of the contribution of FF transitions significantly improves the precision of calculations of theβ--decay half-life.By fitting of the RQRPA results for neutron-rich Z=47,57 isotopes and N=80,94 isotones,the formula for the contribution of the FF transitions gives similar results as the RQRPA calculations.However,because of limited experimental data for the branching ratios of unstable nuclei,the fit parameters are not fully constrained.Therefore,the proposed formula for theβ--decay half-life is more suitable for calculations of half-lives than of the FF contributions.The formula could be used to predict theβ?-decay half-life in nuclear structure studies as well as nucleosynthesis calculations in stars.展开更多
We have systematically analyzed the experimental β--decay half-lives of waiting point heavy nuclei around neutron number N = 126. A new set of parameters for the exponential formula of β^--decay half-lives is propos...We have systematically analyzed the experimental β--decay half-lives of waiting point heavy nuclei around neutron number N = 126. A new set of parameters for the exponential formula of β^--decay half-lives is proposed. The forbidden transition effects are included in the new set of parameters self-consistently. Theoretical β^--decay half-lives of nuclei around N = 126 are compared with recent theoretical results and experimental data. It is found that the new theoretical results are in better agreement with experimental data. The unknown β^--decay half-lives of some nuclei in this region are predicted for studies on nuclear structure far from stability and the nucleosynthesis in stars.展开更多
基金Supported by National Natural Science Foundation of China(11565010,U1731218,11761161001)the Science and Technology Fund of Guizhou Province((2015)4015,(2016)-4008))the Science and Technology Development Fund(FDCT) of Macao(020/2014/A1,008/2017/AFJ,119/2017/A3)
文摘β-decay half-life is a key quantity for nuclear structure and nucleosynthesis studies.There exist large uncertainties in the contributions of allowed and forbidden transitions to the totalβ-decay life,which limits the resolution of the predictedβ-decay half-life.We systematically study the contribution of the first forbidden(FF)transitions to theβ--decay half-life,and quantify it with a formula based on simple physics considerations.We also propose a new formula for calculation of theβ--decay half-life that includes the FF contribution.It is shown that the inclusion of the contribution of FF transitions significantly improves the precision of calculations of theβ--decay half-life.By fitting of the RQRPA results for neutron-rich Z=47,57 isotopes and N=80,94 isotones,the formula for the contribution of the FF transitions gives similar results as the RQRPA calculations.However,because of limited experimental data for the branching ratios of unstable nuclei,the fit parameters are not fully constrained.Therefore,the proposed formula for theβ--decay half-life is more suitable for calculations of half-lives than of the FF contributions.The formula could be used to predict theβ?-decay half-life in nuclear structure studies as well as nucleosynthesis calculations in stars.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11565010,U1731238,11365006,11761161001Guizhou Province Science and Technology Innovation Talent Team under Grant No.2015(4015)+4 种基金The Innovation Team Foundation of the Education Department of Guizhou Province under Grant No.2014-35the Training Program for Excellent Young Talents in Science and Technology of Guizhou Province under Grant No.2011-29the Scientific Research Program for the Returned Overseas Chinese Scholars of Guizhou Province,under Grant No.2013-03the Science and Technology Development Fund(FDCT) of Macao under Grant Nos.020/2014/A1,008/2017/AFJ,119/2017/A3the Key Program of the Student Scientific Research Foundation for Natural Science of Guizhou Normal University
文摘We have systematically analyzed the experimental β--decay half-lives of waiting point heavy nuclei around neutron number N = 126. A new set of parameters for the exponential formula of β^--decay half-lives is proposed. The forbidden transition effects are included in the new set of parameters self-consistently. Theoretical β^--decay half-lives of nuclei around N = 126 are compared with recent theoretical results and experimental data. It is found that the new theoretical results are in better agreement with experimental data. The unknown β^--decay half-lives of some nuclei in this region are predicted for studies on nuclear structure far from stability and the nucleosynthesis in stars.