Half-lives of Double ${\beta }^{+}$-decay with Two Neutrinos

Abstract

Nuclear double ${\beta }^{-}$-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. C89, 064603 (2014)]. However, double ${\beta }^{+}$-decay (${\beta }^{+}{\beta }^{+})$ with emission of both two positrons and two neutrinos has not been observed up to date. In this article, we perform a systematic analysis on the candidates of double ${\beta }^{+}$-decay, based on the 2012 nuclear mass table. Eight nuclei are found to be the good candidates for double ${\beta }^{+}$-decay and their half-lives are predicted according to the generalization of the systematic law to double ${\beta }^{+}$-decay. As far as we know, there is no theoretical result on double ${\beta }^{+}$-decay of nucleus ${}^{154}Dy$ and our result is the first prediction on this nucleus. This is also the first complete research on eight double ${\beta }^{+}$-decay candidates based on the available data of nuclear masses. It is expected that the calculated half-lives of double ${\beta }^{+}$-decay in this article will be useful for future experimental search of double ${\beta }^{+}$-decay.

9 pages,1 figure,2 tables

References in corpus (6)

• Double Beta Decay, Majorana Neutrinos, and Neutrino Mass
• $0\nu \beta \beta$ and $2\nu \beta \beta$ nuclear matrix elements, QRPA, and isospin symmetry restoration
• Precise half-life values for two neutrino double beta decay
• Measurement of the half-life of the two-neutrino double beta decay of Ge-76 with the Gerda experiment
• Systematic Law for Half-lives of Double $\beta$-decay with Two Neutrinos
• Double beta decay to the first $2^{+}$ state within a boson expansion formalism with a projected spherical single particle basis