The four proton-hole nucleus Pt204 was populated in the fragmentation of an E/A=1 GeV Pb208 beam. The yrast structure of Pt204 has been observed up to angular momentum I=10 by detecting delayed γ-ray transitions originating from metastable states. These long-lived excited states have been identified to have spin-parities of Iπ=(10+), (7-), and (5-) and half-lives of T1/2=146(14)ns, 55(3)μs, and 5.5(7)μs, respectively. The structure of the magic N=126 Pt204 nucleus is discussed and understood in terms of the spherical shell model. The data suggest a revision of the two-body interaction for N=126, Z<82, which determines the evolution of nuclear structure toward the r-process waiting point nuclei.
ASJC Scopus subject areas
- Nuclear and High Energy Physics