CERN Accelerating science

Article
Report number arXiv:1902.11211
Title Shape staggering of mid-shell mercury isotopes from in-source laser spectroscopy compared with Density Functional Theory and Monte Carlo Shell Model calculations
Author(s) Sels, S. (KU Leuven, Dept. Phys. Astron.) ; Day Goodacre, T. (Manchester U. ; CERN) ; Marsh, B.A. (CERN) ; Pastore, A. (York U., England) ; Ryssens, W. (Lyon, IPN) ; Tsunoda, Y. (Tokyo U.) ; Althubiti, N. (Manchester U.) ; Andel, B. (Comenius U.) ; Andreyev, A.N. (York U., England ; JAEA, Ibaraki) ; Atanasov, D. (Heidelberg, Max Planck Inst.) ; Barzakh, A.E. (St. Petersburg, INP) ; Bender, M. (Lyon, IPN) ; Billowes, J. (Manchester U.) ; Blaum, K. (Heidelberg, Max Planck Inst.) ; Cocolios, T.E. (KU Leuven, Dept. Phys. Astron.) ; Cubiss, J.G. (York U., England) ; Dobaczewski, J. (York U., England ; Warsaw U.) ; Farooq-Smith, G.J. (KU Leuven, Dept. Phys. Astron.) ; Fedorov, D.V. (St. Petersburg, INP) ; Fedosseev, V.N. (CERN) ; Flanagan, K.T. (Manchester U.) ; Gaffney, L.P. (West Scotland U. ; KU Leuven, Dept. Phys. Astron.) ; Ghys, L. (SCK-CEN, Mol ; KU Leuven, Dept. Phys. Astron.) ; Heenen, P-H. (Brussels U., PNTPM) ; Huyse, M. (KU Leuven, Dept. Phys. Astron.) ; Kreim, S. (Heidelberg, Max Planck Inst.) ; Lunney, D. (CSNSM, Orsay) ; Lynch, K.M. (CERN) ; Manea, V. (Heidelberg, Max Planck Inst.) ; Palenzuela, Y. Martinez (KU Leuven, Dept. Phys. Astron.) ; Medonca, T.M. (CERN) ; Molkanov, P.L. (St. Petersburg, INP) ; Otsuka, T. (Tokyo U. ; Michigan State U., NSCL ; KU Leuven, Dept. Phys. Astron.) ; Ramos, J.P. (CERN ; Ecole Polytechnique, Lausanne) ; Rossel, R.E. (CERN ; Mainz U., Inst. Phys.) ; Rothe, S. (CERN) ; Schweikhard, L. (Greifswald U.) ; Seliverstov, M.D. (St. Petersburg, INP) ; Spagnoletti, P. (West Scotland U.) ; Van Beveren, C. (KU Leuven, Dept. Phys. Astron.) ; Van Duppen, P. (KU Leuven, Dept. Phys. Astron.) ; Veinhard, M. (CERN) ; Verstraelen, E. (KU Leuven, Dept. Phys. Astron.) ; Welker, A. (Dresden, Tech. U.) ; Wendt, K. (Mainz U., Inst. Phys.) ; Wienholtz, F. (Greifswald U.) ; Wolf, R.N. (Heidelberg, Max Planck Inst.) ; Zadvornaya, A. (KU Leuven, Dept. Phys. Astron.)
Publication 2019-04-13
Imprint 2019-02-28
Number of pages 17
Note 19 pages, 18 figures
In: Phys. Rev. C 99 (2019) 044306
DOI 10.1103/PhysRevC.99.044306
Subject category nucl-th ; Nuclear Physics - Theory ; nucl-ex ; Nuclear Physics - Experiment
Abstract Neutron-deficient $^{177-185}$Hg isotopes were studied using in-source laser resonance-ionization spectroscopy at the CERN-ISOLDE radioactive ion-beam facility, in an experiment combining different detection methods tailored to the studied isotopes. These include either alpha-decay tagging or Multi-reflection Time-of-Flight gating to identify the isotopes of interest. The endpoint of the odd-even nuclear shape staggering in mercury was observed directly by measuring for the first time the isotope shifts and hyperfine structures of $^{177-180}$Hg. Changes in the mean-square charge radii for all mentioned isotopes, magnetic dipole and electric quadrupole moments of the odd-A isotopes and arguments in favor of $I = 7/2$ spin assignment for $^{177,179}$Hg were deduced. Experimental results are compared with Density Functional Theory (DFT) and Monte-Carlo Shell Model (MCSM) calculations. DFT calculations with several Skyrme parameterizations predict a large jump in the charge radius around the neutron $N = 104$ mid shell, with an odd-even staggering pattern related to the coexistence of nearly-degenerate oblate and prolate minima. This near-degeneracy is highly sensitive to many aspects of the effective interaction, a fact that renders perfect agreement with experiment out of reach for current functionals. Despite this inherent diffculty, the SLy5s1 and a modified UNEDF1^{SO} parameterization predict a qualitatively correct staggering that is off by two neutron numbers. MCSM calculations of states with the experimental spins and parities show good agreement for both electromagnetic moments and the observed charge radii. A clear mechanism for the origin of shape staggering within this context is identified: a substantial change in occupancy of the proton $\pi h_{9/2}$ and neutron $\nu i_{13/2}$ orbitals.
Copyright/License Publication: © 2019-2024 authors
preprint: (License: arXiv nonexclusive-distrib 1.0)



Corresponding record in: Inspire


 Record created 2019-04-05, last modified 2024-05-08


Fulltext:
Download fulltext
PDF