
Pavel Golubev
Senior lecturer

Reinterpretation of excited states in 212Po: Shell-model multiplets rather than α-cluster states
Author
Summary, in English
A γ-ray spectroscopic study of 212Po was performed at the Grand Accélérateur National d'Ions Lourds, using the inverse kinematics α-transfer reaction 12C(208Pb,212Po)8Be and the AGATA spectrometer. A careful analysis based on γγ coincidence relations allowed us to establish 14 new excited states in the energy range between 1.9 and 3.3 MeV. None of these states, however, can be considered as candidates for the levels with spins and parities of 1− and 2− and excitation energies below 2.1 MeV, which have been predicted by recent α-cluster model calculations. A systematic comparison of the experimentally established excitation scheme of 212Po with shell-model calculations was performed. This comparison suggests that the six states with excitation energies (spins and parities) of 1744 (4−), 1751 (8−), 1787 (6−), 1946 (4−), 1986 (8−), and 2016 (6−) keV, which previously were interpreted as α-cluster states, may in fact be of positive parity and belong to low-lying shell-model multiplets. This reinterpretation of the structure of 212Po is supported by experimental information with respect to the linear polarization of γ rays, which suggests a magnetic character of the 432-keV γ ray decaying from the state at an excitation energy of 1787 keV to the 6+ yrast state, and exclusive reaction cross sections.
Department/s
- Nuclear physics
Publishing year
2021-11-29
Language
English
Publication/Series
Physical Review C
Volume
104
Issue
5
Full text
Document type
Journal article
Publisher
American Physical Society
Topic
- Subatomic Physics
Keywords
- nuclear structure
- shell-model calculations
- alpha cluster states
- AGATA
- linear polarisation
Status
Published
Project
- Nuclear Structure at the Limits: Isotope-selective Spectroscopy
ISBN/ISSN/Other
- ISSN: 2469-9985