Beta decay of the exotic Tz = -1, -2, $^{56}$Zn nucleus and half-life of various proton-rich Tz = -1 nuclei
Résumé
Preliminary results of an experimental study of the -decay of the exotic Tz = -2, 56Zn nucleus and other proton-rich Tz = -1 nuclei are presented. The ions were produced at GANIL using fragmentation reactions, separated by the LISE3 spectrometer and implanted in a double-sided silicon strip detector surrounded by Ge detectors. The half-lives of 56Zn and four Tz = -1 nuclei in the fp-shell have been measured. While the decay of the Tz = -1 nuclei proceeds essentially by -delayed gamma emission, in the case of 56Zn -delayed proton emission is also observed. Moreover the exotic -delayed gamma-proton decay is seen for the rst time. The information from the decay study has been used to determine the absolute Fermi and Gamow- Teller transition strengths. The results for 56Zn have been compared with the mirror Charge Exchange process, the (3He,t) reaction on the Tz = +2, 56Fe target nucleus. This comparison is important for understanding the 56Zn decay data.