Nuclear theory

Large-scale shell model calculation

Nuclear ground-state mass calculation

Nuclear mass is a fundamental quantity in nucleus and equals to total energy of it because of the equivalence of mass and energy, therefore determines the stability of nucleus, governs its decay, and influences the reaction.
We have developed an original model based on the macroscopic and mean-field models to describe the global features of nuclear masses, called the KTUY (Koura-Tachibana-Uno-Yamada) nuclear mass model. This model can describe systematical properties of nuclei as the nuclear closed-shell structure (prediction of change of magicities, and those in the super and extremely super-heavy mass region), nuclear shapes (prediction of shape transition in the neutron-rich, or superheavy mass region)
By using this model, Comprehensive decay-mode calculations have been performed in which α-decay, β-decay, spontaneous fission, proton emission are considered. We are particularly focusing on the β-decay and accompanied phenomena like the β-delayed neutron emission, which affects the safety of nuclear reactors.