2ν double beta decay and self-consistent self-energies

We have performed quasiparticle-random-phase-approximation (QRPA) calculations of the νν transition matrix for ${}_{}{}^{76}{}_{}{}^{}\mathrm{Ge}$, ${}_{}{}^{82}{}_{}{}^{}\mathrm{Se}$, and ${}_{}{}^{100}{}_{}{}^{}\mathrm{Mo}$, using effective interactions derived from the Paris and the Bonn NN potentials. Unlike earlier QRPA calculations where the self-energy corrections to the single-particle spectra were suppressed, we have retained these corrections as given by our interactions. In this way our calculations are able to avoid the commonly encountered difficulty of QRPA instability near ${\mathit{g}}_{\mathrm{pp}}$=1. The ${\mathit{M}}^{2\nu }$ matrix elements of ${}_{}{}^{76}{}_{}{}^{}\mathrm{Ge}$, ${}_{}{}^{82}{}_{}{}^{}\mathrm{Se}$, and ${}_{}{}^{100}{}_{}{}^{}\mathrm{Mo}$ given by our calculation, with no adjustable parameters, are in reasonably good agreement with recent direct counter experiments.