Spectroscopy along flerovium decay chains. II. Fine structure in odd- A Fl289

Fifteen correlated α-decay chains starting from the odd-A superheavy nucleus Fl289 were observed following the fusion-evaporation reaction Ca48+Pu244. The results call for at least two parallel α-decay sequences starting from at least two different states of Fl289. This implies that close-lying levels in nuclei along these chains have quite different spin-parity assignments. Further, observed α-electron and α-photon coincidences, as well as the α-decay fine structure along the decay chains, suggest a change in the ground-state spin assignment between Cn285 and Ds281. Our experimental results, on the excited level structure of the heaviest odd-N nuclei to date, provide a direct testing ground for theory. This is illustrated by comparison with new nuclear structure calculations based on the symmetry-conserving configuration mixing theory.Received 12 April 2022Revised 1 September 2022Accepted 16 December 2022DOI:https://doi.org/10.1103/PhysRevC.107.L021301Published 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 decayLow & intermediate energy heavy-ion reactionsNuclear structure & decaysPropertiesA ≥ 220TechniquesNuclear density functional theoryNuclear Physics