1. |
- Fujita, Y, et al.
(author)
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Evidence for the existence of the [202]3/2 deformed band in mirror nuclei Mg-25 and Al-25
- 2004
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In: Physical Review Letters. - 1079-7114. ; 92:6
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Journal article (peer-reviewed)abstract
- After 50 years of its prediction, the highest-lying [2 0 2]3/2 orbit among the six Nilsson single-particle orbits originating from the sd shells in prolately deformed nuclei and the rotational band on this orbit were identified. The band members were observed in Al-25 at excitation energies of 6-7.5 MeV in a high-resolution Mg-25(He-3,t) charge-exchange reaction at 0degrees having a strong selectivity for Gamow-Teller transitions. In the comparison with the analogous M1 transitions in Mg-25, the J(pi)=3/2(+) bandhead state and the excited 5/2(+) and 7/2(+) members were clearly assigned.
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2. |
- Fujita, Y., et al.
(author)
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Identification of the [202]3/2 deformed band in mirror nuclei Mg-25 and Al-25 and implications for unstable nuclei
- 2006
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In: Physica Scripta. - 0031-8949. ; T125, s. 194-195
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Journal article (peer-reviewed)abstract
- Fifty years after its prediction, the highest-lying [ 2 0 2] 3) 2 orbit among the six Nilsson single-particle orbits originating from the sd shell in prolately deformed nuclei and the rotational band on this orbit were identified. The band members were observed in Al-25 at excitation energies of 6-7.5MeV in a high-resolution Mg-25(He-3,t) charge-exchange reaction at 0 degrees having a strong selectivity for Gamow-Teller transitions. In comparison with the analogous M1 transitions in Mg-25, the J(pi) = 3/+ band-head state and the excited 5/+ and 7/2+ members were clearly assigned.
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3. |
- Shimbara, Y, et al.
(author)
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Suppression of Gamow-Teller and M1 transitions in deformed mirror nuclei Mg-25 and Al-25 - Direct observation of K selection rules
- 2004
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In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 19:1, s. 25-31
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Journal article (peer-reviewed)abstract
- The mirror nuclei Mg-25 and Al-25 are expected to have very similar structures. The Gamow-Teller (GT) transitions from the J(pi) = 5/2(+) ground state of Mg-25 to the excited states in Al-25 were studied by high-resolution measurements of the Mg-25(He-3,t) charge-exchange reaction at 0degrees and at 140 MeV/nucleon. Assuming the usual DeltaJ(pi) = 1(+) selection rule for the spin-isospin-type GT transitions, the states with J(pi) = 3/2(+), 5/2(+), and 7/2 (+) should be excited. However, of the more than ten states with these J(pi) values below 6 MeV excitation energy, only the 5/2 (+) ground state and the 7/2 (+) , 1.613 MeV state in Al-25 were strongly populated, while all other states were strongly suppressed. The analysis of M1 transitions in Mg-25 also suggested a very similar feature for the analogous M1 transitions. Both Mg-25 and Al-25 are known to be largely deformed, and most low-lying states can be interpreted in terms of one-particle quantum numbers in the deformed potential and the associated rotational spectra. The observed suppression can be explained in terms of the K quantum number selection rules that are inherent to axially deformed nuclei.
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