Beta-decay rate and beta-delayed neutron emission probability of improved gross theory

Koura, Hiroyuki   

An improvement of the gross theory of the decay has been carried out on -decay rate, , and beta-delayed neutron emission probability, . The gross theory is based on the sum rule of the -decay strength function, and has succeeded in describing -decay rate of nuclei in the entire nuclear region. The gross theory includes not only the allowed (Fermi and Gamow-Teller) transition, but also the 1st-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction for the nuclear level density and the nuclear deformation for the strength function, those effects were not included in the original gross theory. Considering the properties of the integrated Fermi function, three energy regions of the decay are classified: a higher energy region, which fully affects , a middle energy region, which contributes the decay heat, and a region neighboring the ground-state, which determines . Some results will be given in the presentation.