Doubly magic nucleus Hs162108270

Abstract

Theoretical calculations predict Hs270 (Z=108, N=162) to be a doubly magic deformed nucleus, decaying mainly by α-particle emission. In this work, based on a rapid chemical isolation of Hs isotopes produced in the Mg26+Cm248 reaction, we observed 15 genetically linked nuclear decay chains. Four chains were attributed to the new nuclide Hs270, which decays by α-particle emission with Qα=9.02±0.03MeV to Sg266 which undergoes spontaneous fission with a half-life of 444-148+444ms. A production cross section of about 3 pb was measured for Hs270. Thus, Hs270 is the first nucleus for which experimental nuclear decay properties have become available for comparison with theoretical predictions of the N=162 shell stability. © 2006 The American Physical Society.