NON-COLLAPSING RENORMALIZED QRPA WITH PROTON-NEUTRON PAIRING FOR NEUTRINOLESS DOUBLE-BETA DECAY

Using the renormalized quasiparticle random phase approximation (RQRPA ), we calculate the light neutrino mass mediated mode of neutrinoless double beta decay (0 nu beta beta-decay) of Ge-76, Mo-100, Te-128 and Te-130. Our results indicate that the simple quasiboson approximation is not good enough to study the 0 nu beta beta-decay, because its solu tions collapse for physical values of g(pp). We find that extension of the Hilbert space and inclusion of the Pauli principle in the QRPA wi th proton-neutron pairing, allows us to extend our calculations beyond the point of collapse, for physical values of the nuclear force stren gth. As a consequence one might be able to extract more accurate value s on the effective neutrino mass by using the best available experimen tal limits on the half-life of 0 nu beta beta-decay.