| 1. |
- Andreoiu, Corina, et al.
(author)
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Doorway States in the Gamma Decay-out of the Yrast Superdeformed Band in 59Cu
- 2003
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In: Physical Review Letters. - 1079-7114. ; 91:23
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Journal article (peer-reviewed)abstract
- The decay-out process of the yrast superdeformed band in Cu-59 has been investigated. The firm determination of spin, parity, excitation energy, and configuration of the states involved in this process constitutes a unique situation for a detailed understanding of the decay-out mechanism. A theoretical model is introduced that includes a residual interaction and tunneling matrix element between bands, calculated in the configuration-dependent cranked Nilsson-Strutinsky model. This interaction causes the decay to occur via a small number of observed doorway states.
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| 2. |
- Andreoiu, Corina, et al.
(author)
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Evolution of Shapes in 59Cu
- 2002
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In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 14:3, s. 317-348
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Journal article (peer-reviewed)abstract
- High-spin states in Cu-59 were populated using the fusion-evaporation reaction Si-28 + Ca-40 at a beam energy of 122 MeV. The Gammasphere Ge-detector array in conjunction with the 4pi charged-particle detector array Microball allowed for the detection of gamma-rays in coincidence with evaporated light particles. The resulting extensive high-spin decay scheme of Cu-59 is presented, which comprises more than 320 gamma-ray transitions connecting about 150 excited states. Their spins and parities have been assigned via directional correlations of gamma-rays emitted from oriented states. Average quadrupole moments of rotational bands have been determined from the analysis of residual Doppler shifts. Shell model calculations in the fp shell are invoked to study some of the low-spin states, while the experimental characteristics of the rotational bands are analyzed in the configuration-dependent cranked Nilsson-Strutinsky (CNS) approach.
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| 3. |
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| 4. |
- Chiara, CJ, et al.
(author)
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Transition Quadrupole Moments in the Superdeformed Band of 40Ca
- 2003
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 67:4
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Journal article (peer-reviewed)abstract
- The transition quadrupole moments Q(t) for the superdeformed band in Ca-40 have been determined through thin-target Doppler-shift attenuation analyses. A best-fit value of Q(t)=1.30+/-0.05 e b is obtained when a single value is assumed for the entire band. Fitting separate quadrupole moments for in-band transitions decaying from the high-spin states and the presumably admixed low-spin states results in Q(t)(high)= 1.81(-0.26)(+0.41) e b and Q(t)(low)=1.18(-0.05)(+0.06) e b, respectively. Q(t) values extracted for individual transitions in a Doppler-broadened line-shape analysis also indicate smaller Q(t) values at lower spins. These results are consistent with the interpretation of this band as an eight-particle-eight-hole superdeformed band with a significant admixture of less-collective configurations at low spins.
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| 5. |
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| 6. |
- du Rietz, Rickard, et al.
(author)
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Investigation of High-spin States in 53Fe
- 2005
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 72:1
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Journal article (peer-reviewed)abstract
- The fusion-evaporation reactions Si-28(S-32,1 alpha 2p1n)Fe-53 at 125 MeV and Mg-24(S-32,2p1n)Fe-53 at a 95-MeV beam energy were used to investigate excited states in Fe-53. The combination of the Gammasphere Ge detector array and ancillary devices led to the construction of an extensive level scheme comprising some 90 transitions connecting 40 states. The lifetime of the yrast 25/2(-) state and upper limits for the lifetimes of a number of additional states were determined using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The experimental results are compared to large-scale shell-model calculations using different sets of two-body matrix elements. In particular, predictions on electromagnetic decay properties such as lifetimes, branching ratios, and mixing ratios are studied in detail.
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| 7. |
- Ekman, Jörgen, et al.
(author)
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Core Excited States in the A=51 Mirror Nuclei
- 2004
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 70:5
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Journal article (peer-reviewed)abstract
- Three previously unknown high-energy gamma-ray transitions between 4.2 and 5.4 MeV were identified in the T-z=-1/2 nucleus Fe-51 following the fusion-evaporation reaction S-32(Si-28, 2alpha1n)Fe-51. These transitions represent decays of core excited states. The gamma rays were detected in the Ge detector array Gammasphere combined with the neutron detector system Neutron Shell and the charged-particle array Microball. The three transitions are related to the mirror transitions in the T-z= + 1 /2 nucleus Mn-51, and the resulting mirror-energy difference diagram is discussed with predictions from large-scale shell-model calculations.
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| 8. |
- Ekman, Jörgen, et al.
(author)
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Evidence for a 1g9/2 Rotational Band in 51Mn
- 2002
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 66:5, s. 513011-513015
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Journal article (peer-reviewed)abstract
- A terminating rotational band has been identified in Mn-51 following the Si-28(S-32,2alpha1p)Mn-51 fusion-evaporation reaction at 130 MeV beam energy. Spins and tentative positive parities of the band members are assigned based on angular distribution and correlation measurements of transitions, which connect the rotational structure with previously known yrast states. Configuration-dependent cranked Nilsson-Strutinsky calculations suggest a configuration of the band, which comprises one particle in the 1g(9/2) intruder orbit.
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| 9. |
- Ekman, Jörgen, et al.
(author)
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Gamma-ray Spectroscopy of Core-excited States in 51Mn
- 2004
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 70:1
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Journal article (peer-reviewed)abstract
- The level scheme of Mn-51 has been investigated using the Si-28(S-32 2alpha1p)Mn-51 fusion-evaporation reaction at 125 MeV beam energy. The gamma rays were detected in the Ge-detector array Gammasphere, which was coupled to the 4pi-charged-particle detector Microball and the Neutron Shell for the coincident detection of evaporated particles. Over 100 new gamma-ray transitions connecting some 50 excited states have been identified. Most of the states are built on particle-hole excitations across the shell gaps at particle number N=Z=28. The rich experimental data allows for a 'comprehensive comparison of core-excited states with results from large-scale shell-model calculations, which are known to provide excellent predictions for the lower-lying yrast and near-yrast levels in 1f(7/2) nuclei.
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| 10. |
- Evans, AO, et al.
(author)
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Magnetic properties of smooth terminating dipole bands in Te-110,Te-112
- 2006
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In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 636:1, s. 25-30
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Journal article (peer-reviewed)abstract
- Three strongly coupled sequences have been established in Te-110,Te-112 up to high spins. They are interpreted in terms of deformed structures built on proton 1-particle-1-hole excitations that reach termination at I similar to 40h. This is the first observation of smooth terminating dipole structures in this mass region. Lifetime measurements have allowed the extraction of experimental B(M 1; 1 -> I - 1) and B(E2; I -> I - 2) reduced transition rates for one of the dipole bands in Te-110. The results support the deformed interpretation. (c) 2006 Elsevier B.V. All rights reserved.
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