First measurement of the β-decay half-life of 206Au

The β decay of the N = 127 isotone 206Au has been investigated at the Gesellschaft für Schwerionenforschung laboratory within the rare isotope investigations at GSI Collaboration. From the experimental data, both its half-life and the level structure of the N = 126 daughter nucleus 206Hg have been extracted. On the basis of the new results, the systematics of Au β-decay half-lives beyond the N = 126 shell closure is discussed. In addition, the interplay between allowed Gamow-Teller and first-forbidden transitions in the N > 126, Z < 82 mass region is reviewed.