1. |
- Bentley, M. A., et al.
(författare)
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Isospin symmetry of odd-odd mirror nuclei: Identification of excited states in N=Z-2 Mn-48
- 2006
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Ingår i: Physical Review Letters. - 1079-7114. ; 97:13: 132501
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Tidskriftsartikel (refereegranskat)abstract
- Excited states have been observed in the N=Z-2 odd-odd nucleus Mn-48 for the first time. Through comparison with the structure of V-48, a first high-spin study of an odd-odd mirror pair has been achieved. Differences between the T=1 analogue states in this pair have been interpreted in terms of Coulomb effects, with the aid of shell-model calculations in the full pf valence space. Unlike other mirror pairs, the energy differences have been interpreted almost entirely as due to a monopole effect associated with smooth changes in radius (or deformation) as a function of angular momentum. In addition, the large energy shift between analogue negative-parity states is interpreted in terms of the electromagnetic spin-orbit interaction in nuclei.
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2. |
- Rudolph, D., et al.
(författare)
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Experimental and shell-model study of excited states in 55Fe29 and related notes on 55Cu26
- 2021
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 104:4
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Tidskriftsartikel (refereegranskat)abstract
- The fusion-evaporation reaction 32S+28Si at 125-MeV beam energy was used to populate excited states in 55Fe. Combining the Gammasphere spectrometer with ancillary devices including the Microball CsI(Tl) array and a shell of neutron detectors, a comprehensive level scheme could be derived. The experimental results are compared with theoretical results from shell-model calculations. Taking into account isospin-symmetry breaking terms is found to considerably improve the shell-model description for 55Fe. This motivated a predictive case study of near-yrast states in the mirror nucleus 55Cu.
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3. |
- Rudolph, D., et al.
(författare)
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Single-particle and collective excitations in the N=28 isotones 54Fe and 53Mn
- 2020
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985. ; 102:1
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Tidskriftsartikel (refereegranskat)abstract
- The fusion-evaporation reaction 32S + 28Si at 125 MeV beam energy was used to populate high-spin states in the semimagic N = 28 nuclei 53Mn and 54Fe. With a combination of the Gammasphere spectrometer and ancillary devices including the Microball CsI(Tl) array, extensive high-spin level schemes are derived. They exhibit rotational-like collective structures and competing single-particle excitations. The experimental results are compared with predictions from shell-model calculations, for which the inclusion of isopin-symmetry-breaking terms is found to improve the description. An interpretation of the high-spin states is put forward using cranked Nilsson-Strutinsky calculations, indicative of contributions from collective excitations beyond some 8-MeV excitation energy and highlighting the importance of the g9/2 intruder orbital in this energy range.
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4. |
- Rudolph, Dirk, et al.
(författare)
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Isospin and Deformation Studies in the Odd-odd N = Z Nucleus 54Co
- 2010
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 82:5
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in the odd-odd N = Z nucleus Co-54 have been investigated by the fusion-evaporation reaction Si-28(S-32,1 alpha 1p1n)Co-54. Gamma-ray information gathered with the Ge detector array Gammasphere was correlated with evaporated particles detected in the charged particle detector system Microball and a 1 pi neutron detector array. A significantly extended excitation scheme of Co-54 is presented, which includes a candidate for the isospin T = 1, 6(+) state of the 1f(7/2)(-2) multiplet. The results are compared to large-scale shell-model calculations in the fp shell. Effective interactions with and without isospin-breaking terms have been used to probe isospin symmetry and isospin mixing. A quest for deformed high-spin rotational cascades proved negative. This feature is discussed by means of cranking calculations.
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5. |
- Gadea, A., et al.
(författare)
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Observation of Ni-54 : Cross-conjugate symmetry in f(7/2) mirror energy differences
- 2006
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:15, s. 152501-
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Tidskriftsartikel (refereegranskat)abstract
- Gamma decays from excited states up to J(pi)=6(+) in the N=Z-2 nucleus Ni-54 have been identified for the first time. Level energies are compared with those of the isobars Co-54 and Fe-54 and of the cross-conjugate nuclei of mass A=42. The good but puzzling f(7/2) cross-conjugate symmetry in mirror and triplet energy differences is analyzed. Shell model calculations reproduce the new data but the necessary nuclear charge-dependent phenomenology is not fully explained by modern nucleon-nucleon potentials.
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