Spectroscopy along flerovium decay chains. III. Details on experiment, analysis, Cn282 , and spontaneous fission branches

Flerovium isotopes (element Z=114) were produced in the fusion-evaporation reactions Ca48+Pu242,244 and studied with an upgraded TASISpec decay station placed in the focal plane of the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. Twenty-nine flerovium decay chains were identified by means of correlated implantation, α decay, and spontaneous fission events. Data analysis aspects and statistical assessments, primarily based on measured rates of various events, which laid the foundation for the comprehensive spectroscopic information on the flerovium decay chains, are presented in detail. Various decay scenarios of an excited state observed in Cn282 are examined in depth with the help of Geant4 simulations and assessed by predictions of beyond mean-field calculations including triaxial shape degrees of freedom. Previous, revised, and newly derived fission probabilities of even-even superheavy nuclei are compared with various theoretical predictions.Received 12 April 2022Revised 19 December 2022Accepted 4 January 2023DOI:https://doi.org/10.1103/PhysRevC.107.024301Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by Bibsam.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasAlpha decayFissionNuclear structure & decaysNuclear Physics