BETA DECAY OF THE EXOTIC T-z =-2, Zn-56 NUCLEUS AND HALF-LIFE OF VARIOUS PROTON-RICH T-z =-1 NUCLEI

Abstract

Preliminary results of an experimental study of the beta-decay of the exotic T-z = -2, Zn-56 nucleus and other proton-rich T-z = 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 Zn-56 and four T-z= - 1 nuclei in the fp-shell have been measured. While the decay of the Tz = 1 nuclei proceeds essentially by beta-delayed gamma emission, in the case of 56Zn beta-delayed proton emission is also observed. Moreover, the exotic beta-delayed gamma-proton decay is seen for the first time. The information from the decay study has been used to determine the absolute Fermi and Gamow Teller transition strengths. The results for Zn-56 have been compared with the mirror Charge Exchange process, the (He-3,t) reaction on the Tz = +2, Fe-56 target nucleus. This comparison is important for understanding the Zn-56 decay data.