부산대학교 도서관

Abstract: : Under the assumption that isospin is a good quantum number, symmetry is expected for the transitions from the ground states of T = 1, Tz = ±1 nuclei to the common excited states of the Tz = 0 nucleus situated between the two nuclei. The symmetry can be studied by comparing the strengths of Gamow-Teller (GT) transitions obtained from a (p, n)-type charge-exchange reaction on a target nucleus with Tz = 1 with those from the β-decay of the Tz = - 1 nucleus. The A = 58 system is the heaviest for which such a comparison is possible. As a part of the symmetry study, we measured the GT transitions from 58Ni (Tz = 1) to 58Cu (Tz = 0) by using the zero-degree (3He, t) reaction at 150 MeV/nucleon. With the achieved resolution of 50 keV, many hitherto unresolved GT states have been identified. The GT transition strengths were obtained for states up to 8 MeV excitation, i.e., near to the Q window limitation ( QEC = 9.37 MeV) of the β-decay from 58Zn (Tz = - 1) to 58Cu. The strength distribution is compared with that from shell-model calculations.