Abstract
Gamow-Teller (GT) transitions starting from unstable pf-shell nuclei play important roles in neutrino-induced reactions that happen under the extremely high temperature conditions in core-collapse (type 11) supernovae. In the 0 decay, it is difficult to obtain GT strengths B(GT) to higher excited states, but accurate half-lives can be measured. On the other hand, high-resolution (He-3,t) charge-exchange reactions at 0 degrees and at 420 MeV yield cross-sections, that are proportional to B(GT) values, for individual transitions up to high excitation. Assuming isospin symmetry, we performed a unique analysis to determine absolute B(GT) values for the T-z = +/-1 --> 0 analogous GT transitions. Further P-decay studies for unstable pf-shell nuclei to obtain accurate half-lives and feeding ratios are in progress.