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New features of shape coexistence in ;{152}Sm
P E Garrett1, W D Kulp, J L Wood
1Department of Physics, University of Guelph, Guelph, Ontario, N1G2W1 Canada.
Physical Review Letters
|October 2, 2009
Summary
Researchers studied excited states in Samarium-152 (¹⁵²Sm) using nuclear reactions. A new octupole excitation was identified, suggesting complex shape coexistence in the nucleus.
Area of Science:
- Nuclear Physics
- Atomic Physics
Background:
- Understanding nuclear structure is crucial for nuclear physics.
- Excited states in atomic nuclei provide insights into fundamental forces.
Purpose of the Study:
- Investigate excited states in Samarium-152 (¹⁵²Sm).
- Characterize negative-parity band structures and decay properties.
- Identify and assign new octupole excitations.
Main Methods:
- Utilized the ¹⁵²Sm(n,n'γ) nuclear reaction.
- Analyzed decay properties of excited states.
- Determined energy levels and transition rates.
Main Results:
- Characterized the lowest four negative-parity band structures in ¹⁵²Sm.
- Assigned a new Kπ = 0⁻ band with its head at 1681 keV.
- Observed similar E1 transition rates to the Kπ = 0⁺ band as the ground-state band decay.
Conclusions:
- The new band is assigned as a Kπ = 0⁻ octupole excitation based on the Kπ = 0₂⁺ state.
- The emerging pattern suggests ¹⁵²Sm exhibits complex shape coexistence.
- This challenges the notion of ¹⁵²Sm being a simple critical point nucleus.
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