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Title: Identification of the one-quadrupole phonon 2 1 , m s + state of 204Hg

One-phonon states of vibrational nuclei with mixed proton–neutron symmetry have been observed throughout the nuclear chart besides the mass A ≈ 200 region. Very recently, it has been proposed that the 2 + 2 state of 212Po is of isovector nature. This nucleus has two valence protons and two valence neutrons outside the doubly-magic 208Pb nucleus. The stable isotope 204Hg, featuring two valence-proton and valence-neutron holes, with respect to 208Pb, is the particle-hole mirror of 212Po. In order to compare the properties of low-lying isovector excitations in these particle-hole mirror nuclei, we have studied 204Hg by using the projectile Coulomb-excitation technique. The measured absolute B( M1;2 + 2 → 2 + 1) strength of 0.20 (2) μ 2 N indicates that the 2 + 2 level of 204Hg is at least the main fragment of the 2 + 1,ms state. For the first time in this mass region, both lowest-lying, one-quadrupole phonon excitations are established together with the complete set of their decay strengths. In conclusion, this allows for a microscopic description of their structures, achieved in the framework of the Quasi-particle Phonon Model.
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  1. Technische Univ. Darmstadt, Darmstadt (Germany)
  2. Univ. of Sofia St. Kliment Ohridski, Sofia (Bulgaria)
  3. Bulgarian Academy of Sciences, Sofia (Bulgaria)
  4. Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Grant/Contract Number:
Published Article
Journal Name:
Physics Letters. Section B
Additional Journal Information:
Journal Volume: 770; Journal Issue: C; Journal ID: ISSN 0370-2693
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
Country of Publication:
United States
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; γ ray spectroscopy; Coulomb excitation; Quadrupole collectivity; Isospin degree of freedom; Shell structure
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1389632