First application of the continuum-QRPA to description of the double beta decay

A continuum-QRPA approach to calculation of the $2\nu\beta\beta$- and $0\nu\beta\beta$-amplitudes has been formulated. For $^{130}$Te a regular suppression (about 20%) of the high-multipole contributions to the $0\nu\beta\beta$-amplitude has been found which can be associated with additional ground state correlations appearing from the transitions to collective states in the continuum. At the same time the total calculated $0\nu\beta\beta$-amplitude for $^{130}$Te gets suppressed by about 20% as compared to the result of the usual, discretized, QRPA.