Experimental data ofβ--decay half-lives of nuclei with atomic number between 20 and 190 are investigated.A systematic formula has been proposed to calculateβ^--decay half-lives of neutron-rich nuclei,with a particul...Experimental data ofβ--decay half-lives of nuclei with atomic number between 20 and 190 are investigated.A systematic formula has been proposed to calculateβ^--decay half-lives of neutron-rich nuclei,with a particular consideration on shell and pair effects,the decay energy Q as well as the nucleon numbers(Z,N).Although the formula has relatively few parameters,it reproduces the experimentalβ^--decay half-lives of neutron-rich nuclei very well.The predicted half-lives for the r-process relevant nuclei obtained with the current formula serve as reliable input in the r-process model calculations.展开更多
Nuclear double β^--decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys Rev C, 2014, 89： 06...Nuclear double β^--decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys Rev C, 2014, 89： 064603]. However, double β^＋ -decay （β^＋β^＋） with emission of both two positrons and two neutrinos has not been observed up to date. In this article, we pcrform a systematic analysis on the candidates of double β^＋-decay, based on the 2012 nuclear mass table. Eight nuclei are found to be the good candidates for double β^＋-decay and their half-lives are predicted according to the generalization of the systematic law to double β^＋-decay. As far as we know, there is no theoretical result on double β^＋-decay of nucleus ^154Dy and our result is the first prediction on this nucleus. This is also the first complete research on eight double β^＋-decay candidates based on the available data of nuclear masses. It is expected that the calculated half-lives of double β^＋-decay in this article will be useful for future experimental search of double β^＋-decay.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11490563 and 11375269)the National Basic Research Program of China(Grant No.2013CB834406)the National Key Research and Development Program of China(Grant No.2016YFA0400502)
文摘Experimental data ofβ--decay half-lives of nuclei with atomic number between 20 and 190 are investigated.A systematic formula has been proposed to calculateβ^--decay half-lives of neutron-rich nuclei,with a particular consideration on shell and pair effects,the decay energy Q as well as the nucleon numbers(Z,N).Although the formula has relatively few parameters,it reproduces the experimentalβ^--decay half-lives of neutron-rich nuclei very well.The predicted half-lives for the r-process relevant nuclei obtained with the current formula serve as reliable input in the r-process model calculations.
基金supported by the National Natural Science Foundation of China(Grant Nos.11035001,10975072,11120101005,11175085 and11375086)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Nuclear double β^--decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys Rev C, 2014, 89： 064603]. However, double β^＋ -decay （β^＋β^＋） with emission of both two positrons and two neutrinos has not been observed up to date. In this article, we pcrform a systematic analysis on the candidates of double β^＋-decay, based on the 2012 nuclear mass table. Eight nuclei are found to be the good candidates for double β^＋-decay and their half-lives are predicted according to the generalization of the systematic law to double β^＋-decay. As far as we know, there is no theoretical result on double β^＋-decay of nucleus ^154Dy and our result is the first prediction on this nucleus. This is also the first complete research on eight double β^＋-decay candidates based on the available data of nuclear masses. It is expected that the calculated half-lives of double β^＋-decay in this article will be useful for future experimental search of double β^＋-decay.
