$0\nu \beta \beta$ and $2\nu \beta \beta$ nuclear matrix elements in the interacting boson model with isospin restoration

Abstract

We introduce a method for isospin restoration in the calculation of nuclear matrix elements (NME) for $0\nu \beta \beta$ and $2\nu \beta \beta$ decay within the framework of interacting boson model (IBM-2). With this method, we calculate NME for all processes of interest in $0\nu {\beta }^{-}{\beta }^{-}$, $2\nu {\beta }^{-}{\beta }^{-}$, and in $0\nu {\beta }^{+}{\beta }^{+}$, $0\nu {\beta }^{+}E{C}^{+}$, $R0\nu ECEC$, $2\nu {\beta }^{+}{\beta }^{+}$, $2\nu {\beta }^{+}EC$, and $2\nu ECEC$. With this method, the Fermi (F) matrix elements for $2\nu \beta \beta$ vanish, and those for $0\nu \beta \beta$ are considerably reduced.

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