β decay of the proton-richTz=−1/2nucleus,71Kr

Abstract

{beta} decay of the T{sub z}={minus}1/2 nuclide {sup 71}Kr has been studied at the ISOLDE PSB Facility at CERN. {sup 71}Kr ions were produced in spallation reactions in a Nb foil using the 1 GeV proton beam and studied by means of {beta}-delayed proton, {beta}- and {gamma}-ray spectroscopy. The half-life and the {beta}-decay energy of {sup 71}Kr were determined using the decay of protons and positrons. These results: T{sub 1/2}=100{plus_minus}3ms and Q{sub EC}=10.14{plus_minus}0.32MeV and the first observation of the {beta} branch to the 207 keV level in {sup 71}Br makes the extension of the systematics of Gamow-Teller matrix elements of mirror nuclei up to A=71 possible. The Gamow-Teller strength of the same magnitude as that of the fp-shell mirror nuclei is observed for the ground-state transition. {copyright} {ital 1997} {ital The American Physical Society}