New shape isomer in the self-conjugate nucleus 72Kr.
A new isomeric 0(+) state was identified as the first excited state in the self-conjugate (N=Z) nucleus 72Kr. By combining for the first time conversion-electron and gamma-ray spectroscopy with the production of metastable states in high-energy fragmentation, the electric-monopole decay of the new isomer to the ground state was established. The new 0(+) state is understood as the band head of the known prolate rotational structure, which strongly supports the interpretation that 72Kr is one of the rare nuclei having an oblate-deformed ground state. This observation gives in fact the first evidence for a shape isomer in a N=Z nucleus.
Bouchez
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E
CEA Saclay, DAPNIA/SPhN, F-91191 Gif-sur-Yvette, France.
Matea
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I
Korten
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W
Becker
F
F
Blank
B
B
Borcea
C
C
Buta
A
A
Emsallem
A
A
de France
G
G
Genevey
J
J
Hannachi
F
F
Hauschild
K
K
Hürstel
A
A
Le Coz
Y
Y
Lewitowicz
M
M
Lucas
R
R
Negoita
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F
de Oliveira Santos
F
F
Pantelica
D
D
Pinston
J
J
Rahkila
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P
Rejmund
M
M
Stanoiu
M
M
Theisen
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Ch