O. Civitarese et al., Extended quasiparticle random phase approximation at finite temperatures: Calculation of single beta-decay Fermi transitions - art. no. 054318, PHYS REV C, 6205(5), 2000, pp. 4318
The formalism of the quasiparticle random phase approximation, extended to
include scattering terms in the equation of motion, is used to describe all
owed single beta -decay transitions of Fermi type at finite temperatures. T
he calculations were performed by using a realistic single particle basis a
nd a separable two body interaction in the proton-neutron channel. The beha
vior of the Ikeda sum rule is studied and it is found that this sum rule is
strictly conserved in the presence of particle-particle and hole-hole corr
elations. As an example on the validity of the formalism the case of Fermi
transitions in Ge-76 is considered.