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.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.
