Beyond Mean-field Description of Nuclear Gamow-Teller Resonance and β-decay Half-lives

Nuclear β decay is one of the key nuclear processes that determine how the heavy elements from Fe to U in the universe were made. The dominant nuclear process in β-decay is the Gamow-Teller(GT) transition, so the key point for nuclear β-decay study is to describe nuclear GT transition accurately. One of the most widely used nuclear model is random phase approximation (RPA). However, since it only includes one-particle one-hole excitation configurations, this model cannot describe spreading width of GT resonance, and tends to overestimate the β-decay half-lives. To overcome these difficulties, based on Skyrme density functional, the random phase approximation with particle vibration coupling (RPA+PVC) model was developed. Compared to RPA model, it further includes the one-particle one-hole coupled with phonons in its configuration space, which includes many-body correlations beyond mean field approximation. To extend the study to open shell nuclei, the quasiparticle random phase approximation with quasiparticle vibration coupling model (QRPA+QPVC), which includes pairing correlations, was developed. Based on the above models, the GT excitation, β decay, β⁺/EC of magic nuclei and superfluid nuclei were studied. It is found that with the same Skyrme interaction SkM*, the experimental GT width and transition strength profile were well reproduced, the quenching phenomenon was partly explained, and the description of β-decay half-lives were improved at the same time. The recent progress of this study is reviewed, and in the meantime the perspectives for future developments are given.