Neutrinoless double positron decay and positron emitting electron capture in the interacting boson model

Abstract

Neutrinoless double-$\beta$ decay is of fundamental importance for determining the neutrino mass. Although double electron (${\beta }^{-}{\beta }^{-}$) decay is the most promising mode, in very recent years interest in double positron (${\beta }^{+}{\beta }^{+}$) decay, positron emitting electron capture ($EC{\beta }^{+}$), and double electron capture ($ECEC$) has been renewed. We present here results of a calculation of nuclear matrix elements for neutrinoless double-${\beta }^{+}$ decay and positron emitting electron capture within the framework of the microscopic interacting boson model (IBM-2) for ${}^{58}$Ni, ${}^{64}$Zn, ${}^{78}$Kr, ${}^{96}$Ru, ${}^{106}$Cd, ${}^{124}$Xe, ${}^{130}$Ba, and ${}^{136}$Ce decay. By combining these with a calculation of phase space factors we calculate expected half-lives.

Comments: arXiv admin note: text overlap with arXiv:1301.4203