Abstract
The behavior of l-forbidden M1 transitions around Z = 50 and N = 82 is investigated. In the decay of 131Ce, lifetimes of excited states in 131La have been measured for the first time as T 1 2(26.2 keV) = 0.85 ± 0.10 ns, T 1 2 (145.5 keV) ≦ 0.3 ns, and T 1 2 (195.5 keV = 0.08 ns. In the decay of 133La, the lifetime of the 12.3 keV state in 133Ba has been measured as T 1 2 (12.3 keV) = 7.0 ± 0.3 ns in contradiction to a recently published result. From the value B(M1, 5 2 → 3 2)exp, possible conclusions on the structure of the ground state in 131La are drawn. All the available data on l-forbidden M1 transitions n(2d 3 2 ↔ 3s 1 2) and p(1g 7 2 ↔ 2d 5 2) in nuclei with 100 < A < 150 are systematically considered. Their remarkable sensitivity towards filling of the jj closed shell N = 82 is discussed in terms of quadrupole deformations. This approach is supported by the systematics of rotational B(M1) values in deformed nuclei (150 < A < 190) found to increase appreciably with increasing quadrupole deformation.
Original language | English (US) |
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Pages (from-to) | 45-60 |
Number of pages | 16 |
Journal | Nuclear Physics, Section A |
Volume | 368 |
Issue number | 1 |
DOIs | |
State | Published - Sep 21 1981 |
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
Keywords
- Radioactivity