Improvement of the Gross Theory of -Decay. II: One-Particle Strength Function

Abstract

An attempt is made to improve the gross theory of nuclear β-decay by modifying the one-particle strength function. For the Gamow-Teller transition, a one-particle strength function having a peak with a long tail on each side is empolyed. The position, height and width parameters of the peak are adjusted so as to reproduce the experimental Gamow-Teller giant resonance. A method for calculating sum rules of the one-particle strength function is proposed to get information on the tail, and the results suggest a much longer length of the tails than that of the previous gross theory. Similar modifications of the one-particle strength function are also made for other transitions, especially for the axial-vector-type first forbidden transitions. Newly calculated β-decay half-lives are briefly discussed in comparison with experimental data.