Deformation and Collectivity in Doubly Magic Pb 208

Authors

• J. Henderson, University of SurreyFollow
• J. Heery, University of Surrey
• M. Rocchini, National Institute for Nuclear Physics
• M. Siciliano, Argonne National Laboratory
• N. Sensharma, Argonne National Laboratory
• A. D. Ayangeakaa, University of North Carolina at Chapel Hill
• R. V.F. Janssens, University of North Carolina at Chapel Hill
• T. M. Kowalewski, University of North Carolina at Chapel Hill
• Abhishek, University of Surrey
• P. D. Stevenson, University of Surrey
• E. Yüksel, University of Surrey
• B. A. Brown, Michigan State University
• T. R. Rodriguez, Universidad Complutense de Madrid
• L. M. Robledo, Universidad Autónoma de Madrid
• C. Y. Wu, Lawrence Livermore National Laboratory
• S. Kisyov, Lawrence Livermore National Laboratory
• C. Müller-Gatermann, Argonne National Laboratory
• V. Bildstein, University of Guelph
• L. Canete, University of Surrey
• C. M. Campbell, Lawrence Berkeley National Laboratory
• S. Carmichael, University of Notre Dame
• M. P. Carpenter, Argonne National Laboratory
• W. N. Catford, University of Surrey
• P. Copp, Argonne National Laboratory
• C. Cousins, University of Surrey
• M. Devlin, Los Alamos National Laboratory
• D. T. Doherty, University of Surrey
• P. E. Garrett, University of Guelph

Abstract

Lead-208 is the heaviest known doubly magic nucleus and its structure is therefore of special interest. Despite this magicity, which acts to provide a strong restorative force toward sphericity, it is known to exhibit both strong octupole correlations and some of the strongest quadrupole collectivity observed in doubly magic systems. In this Letter, we employ state-of-the-art experimental equipment to conclusively demonstrate, through four Coulomb-excitation measurements, the presence of a large, negative, spectroscopic quadrupole moment for both the vibrational octupole 31- and quadrupole 21+ state, indicative of a preference for prolate deformation of the states. The observed quadrupole moment is discussed in the context of the expected splitting of the 3- - 3- two-phonon states, due to the coupling of the quadrupole and octupole motion. These results are compared with theoretical values from three different methods, which are unable to reproduce both the sign and magnitude of this deformation. Thus, in spite of its well-studied nature, Pb208 remains a puzzle for our understanding of nuclear structure.

Document Type

Article

Publication Date

2-14-2025

Notes/Citation Information

Publisher Copyright: © 2025 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"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.

Digital Object Identifier (DOI)

10.1103/PhysRevLett.134.062502

Archival?

Archival

Repository Citation

Henderson, J.; Heery, J.; Rocchini, M.; Siciliano, M.; Sensharma, N.; Ayangeakaa, A. D.; Janssens, R. V.F.; Kowalewski, T. M.; Abhishek; Stevenson, P. D.; Yüksel, E.; Brown, B. A.; Rodriguez, T. R.; Robledo, L. M.; Wu, C. Y.; Kisyov, S.; Müller-Gatermann, C.; Bildstein, V.; Canete, L.; Campbell, C. M.; Carmichael, S.; Carpenter, M. P.; Catford, W. N.; Copp, P.; Cousins, C.; Devlin, M.; Doherty, D. T.; and Garrett, P. E., "Deformation and Collectivity in Doubly Magic Pb 208" (2025). Chemistry Faculty Publications. 252.
https://uknowledge.uky.edu/chemistry_facpub/252