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Interplay between single-particle and collective effects in the odd-A Cu isotopes beyond N=40
I Stefanescu1, G Georgiev, D L Balabanski
1Instituut voor Kern- en Stralingsfysica, K.U. Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Physical Review Letters
|June 4, 2008
Summary
Researchers studied copper isotopes using radioactive beams, revealing new excited states and coexistence of nuclear structures. This finding offers insights into nuclear properties beyond N=40.
Area of Science:
- Nuclear Physics
- Atomic and Molecular Physics
Background:
- Investigating collective properties of low-lying levels in odd-A copper (Cu) isotopes is crucial for understanding nuclear structure.
- Previous studies have identified certain energy states, but a comprehensive understanding, especially beyond neutron number N=40, remains incomplete.
Purpose of the Study:
- To investigate the collective properties of low-lying energy levels in odd-A copper isotopes (67-73Cu).
- To identify and characterize newly observed excited states in 71Cu and 73Cu.
- To determine B(E2) values and understand the nuclear structure evolution in these isotopes.
Main Methods:
- Utilizing Coulomb excitation with radioactive beams produced at ISOLDE and accelerated by REX-ISOLDE.
- Analyzing gamma-ray emissions to identify excited states and transitions.
- Reanalyzing beta-decay data and comparing with isotopic systematics.
Main Results:
- Low-lying 1/2(-), 5/2(-), and 7/2(-) states were populated in 67,69Cu.
- New gamma-ray transitions (454 keV in 71Cu, 135 keV in 73Cu) were observed for the first time, suggesting a spin 1/2(-) for these states.
- Three B(E2) values were determined for each of the four isotopes studied.
Conclusions:
- The study reveals a significant change in the nuclear structure of odd-A Cu isotopes beyond N=40.
- Evidence suggests the coexistence of single-particle-like and collective levels at very low excitation energies in these isotopes.
- The findings contribute to a deeper understanding of nuclear structure evolution in this mass region.
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