  A new consistent analysis of the renormalized proton--neutron quasiparticle
random phase approximation based on the simultaneous recalculation of the
one--body density matrix and the pairing tensor has been used to study the
double beta decay. We demonstrated that inclusion of the quasiparticle
correlations at the BCS level reduces the ground state correlations in the
particle--particle channel of the proton--neutron interaction. We also
simplified the RQRPA equations significantly obtaining a low--dimensioned set
of linear equations for the quasiparticle densities. The formalism was applied
to the double beta decay in ^{76}Ge.
