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New shape isomer in the self-conjugate nucleus 72Kr
Physical Review Letters
|March 14, 2003
Summary
Researchers discovered a new excited state in the self-conjugate nucleus 72Kr, providing the first evidence of a shape isomer in N=Z nuclei. This finding clarifies the nuclear shape of 72Kr, revealing an oblate-deformed ground state.
Area of Science:
- Nuclear Physics
- Atomic Physics
Background:
- The study of nuclear structure in self-conjugate (N=Z) nuclei is crucial for understanding fundamental nuclear forces.
- Identifying isomeric states and their decay properties provides insights into nuclear shapes and configurations.
- Previous research on 72Kr suggested complex nuclear structure, but experimental evidence for shape isomerism was lacking.
Purpose of the Study:
- To identify and characterize new excited states in the self-conjugate nucleus 72Kr.
- To investigate the electric-monopole decay of isomeric states in 72Kr.
- To provide the first experimental evidence for shape isomerism in an N=Z nucleus.
Main Methods:
- Utilized a combination of conversion-electron and gamma-ray spectroscopy.
- Employed high-energy fragmentation techniques to produce metastable states.
- Analyzed decay properties to establish the nature of the new isomeric state.
Main Results:
- Identified a new isomeric 0(+) state as the first excited state in 72Kr.
- Established the electric-monopole decay of this new isomer to the ground state.
- Interpreted the new 0(+) state as the band head of a prolate rotational structure.
Conclusions:
- The findings strongly support the interpretation of 72Kr possessing an oblate-deformed ground state.
- This work presents the first evidence for a shape isomer in a self-conjugate (N=Z) nucleus.
- The observed shape isomerism in 72Kr offers new perspectives on nuclear structure theories.
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