On Gamow-Teller strength distributions for $\beta \beta$-decaying nuclei within continuum-QRPA

An isospin-selfconsistent pn-continuum-QRPA approach is formulated and applied to describe the Gamow-Teller strength distributions for $\beta \beta$-decaying open-shell nuclei. The calculation results obtained for the pairs of nuclei ${}^{76}$Ge-Se, ${}^{100}$Mo-Ru, ${}^{116}$Cd-Sn, and ${}^{130}$Te-Xe are compared with available experimental data.