β decay of even-A nuclei within the interacting boson model based on nuclear density functional theory
Abstract
We compute the β-decay ft-values within the frameworks of the energy density functional (EDF) and the interacting boson model (IBM). Based on the constrained mean-field calculation with the Gogny-D1M EDF, the IBM Hamiltonian for an even-even nucleus and essential ingredients of the interacting boson-fermion-fermion model (IBFFM) for describing the neighboring odd-odd nucleus are determined in a microscopic way. Only the boson-fermion and residual neutron-proton interaction strengths are determined empirically. The Gamow-Teller (GT) and Fermi (F) transition rates needed to compute the β-decay ft-values are obtained without any additional parameter or quenching of the gA factor. The observed values for the β+ decays of the even-even Ba into odd-odd Cs nuclei, and of the odd-odd Cs to the even-even Xe nuclei, with mass A≈ 130 are reasonably well described. The predicted GT and F transition rates represent a sensitive test of the quality of the IBM and IBFFM wave functions.