<![CDATA[This paper presents a model space calculation of the beta decay in the nucleus Yb178 using pure and modified Migdal interactions in the proton-neutron Quasiparticle Random Phase Approximation (pn-QRPA). The single-particle ground states are calculated self-consistently using the Fayans energy density functional in a Hartree-Fock-Bogoliubov (HFB) scheme for deformed nuclei, where the DF3 parameter set has been chosen as it is considered the most suitable parameter set for medium-mass nuclei. The particle-particle pairing parameters are varied such that the correct Lipkin-Nogami pairing gap parameters for protons and neutrons are produced. The quasi-particle states for the pn-QRPA calculation are calculated from the HFB single-particle ground states using the Bardeen-Cooper-Schriefer (BCS) approximation. Two types of excitation interaction are used to excite the daughter nucleus to produce the β- decay: (a) a pure Migdal interaction, and (b) a modified Migdal interaction (Migdal plus a correction term obtained self-consistently from the BCS quasi-particle basis). The calculations using the pure Migdal and modified Migdal interactions give half-lives of 17.35 min and 18.98 min, respectively, i.e about one-fourth of the experimental value of 74 min, but the decay energies (0.61 MeV and 0.59 MeV, respectively) agree with the experimental value (0.64 MeV). Apart from the poor accuracy for the calculated half-lives, the correction term of the Migdal excitation interaction does not improve the accuracy in both the half-life and decay energy. For a more accurate study, the beta decay calculation needs to take into account the subnucleonic resonance (Δ) excitations. The theoretical framework so far has been developed only for even-even nuclei, and further development for nuclei in general is suggested]]>
Copyrights © 2026
