| 1. |
- Marsh, J. C., et al.
(author)
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Identification of triaxial strongly deformed bands in Hf-164
- 2013
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 88:4
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Journal article (peer-reviewed)abstract
- Two new rotational bands of distinct character have been identified in Hf-164. They are suggested to correspond to the long-anticipated triaxial strongly deformed (TSD) bands predicted by theoretical studies. The bands have been linked to known states, and the level spins and energies could be determined. The bands are also substantially stronger in intensity and are located at lower spins than the previously observed TSD bands in Hf-168, hereby making Hf-164 the best even-even system so far for the study of TSD structures in the A similar to 160 mass region. Cranking calculations based on the modified-oscillator model suggest that the bands are associated with four-quasiparticle configurations that involve high-j intruder (i(13/2))(2) proton orbitals.
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| 2. |
- Yadav, R. B., et al.
(author)
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Identification of triaxial strongly deformed bands in Hf-168
- 2008
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 78:4
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Journal article (peer-reviewed)abstract
- Possible decay pathways associated with three candidates for triaxial strongly deformed (TSD) bands in Hf-168 have been investigated. The spin and excitation energy of the strongest band, TSD1, were determined approximately based on gamma-ray coincidence relationships. Discrete links were established for the second band. The overall agreement between the observed properties of the bands and cranking calculations using the ULTIMATE CRANKER code provides strong support for an interpretation where band TSD1 is associated with a TSD minimum, (epsilon(2),gamma)similar to(0.43,20(degrees)), involving the pi(i(13/2))(2) and the nu(j(15/2)) high-j orbitals. This constitutes the first identification of a TSD band in Hf isotopes, which has been long-predicted by theoretical studies. The second band is understood as being associated with a near-prolate shape and a deformation enhanced with respect to the normal deformed bands. It is proposed to be built on the pi(i(13/2)h(9/2))circle times nu(i(13/2))(2) configuration.
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| 3. |
- Al-Khatib, A, et al.
(author)
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Transition to non-collective states at high spin in Xe-124
- 2008
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In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 36:1, s. 21-29
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Journal article (peer-reviewed)abstract
- Excited states in Xe-124 were populated in the reaction Se-82(Ca-48, 6n) Xe-124 and gamma-ray coincidence relationships were measured with the Gammasphere spectrometer. Two new bands are observed and several of the previously known bands are extended in the high-as well as in the low-spin region. Two irregular high-spin structures are also added. The irregularities are a fingerprint of a transition from collective to non-collective behaviour. Configuration assignments to the new structures are proposed on the basis of systematics and by comparing experimental properties with calculations within the framework of the cranking model.
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| 4. |
- Rudolph, Dirk, et al.
(author)
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Isospin and Deformation Studies in the Odd-odd N = Z Nucleus 54Co
- 2010
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 82:5
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Journal article (peer-reviewed)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. |
- Schnack-Petersen, H, et al.
(author)
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Superdeformed triaxial bands in Lu-163,165
- 1995
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In: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 594:2, s. 175-202
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Journal article (peer-reviewed)abstract
- An experimental investigation of the nucleus 165Lu, using the reactions 138Ba(31P,4n) 165Lu and 150Sm(19F,4n) 165Lu at beam energies of E = 155 and 95 MeV, respectively, has been performed. Among other additions to the existing level scheme, a new band, with transition energies almost identical to a strongly deformed (β2 0.42) πi13/2[660 1/2+] band recently discovered in 163Lu has been established. A theoretical analysis of the structure of the two Lu isotopes, 165Lu and 163Lu is carried out by detailed calculations of total potential energy surfaces for specific configurations. By a diabatic treatment of crossings specific proton configurations as πi13/2[660 1/2+] are identified throughout the deformation space and as a function of spin. It is found as a general feature that well deformed local minima of considerable nonaxial symmetry coexist with a normal deformed global minimum. The depth of these local minima depend on configuration. The structure of the different global and local minima found in these surfaces are analysed and discussed in terms of occupation of available basis configurations and their orientation relative to the rotation axis. The strongly deformed minima are found to belong to a group of superdeformed triaxial structures, expected to appear at low energies for certain favourable combinations of proton and neutron numbers.
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| 6. |
- Schonwasser, G, et al.
(author)
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Lifetimes of triaxial superdeformed states in Lu-163 and Lu-164
- 2002
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In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 13:3, s. 291-296
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Journal article (peer-reviewed)abstract
- Lifetimes of states in the yrast superdeformed bands of Lu-163 and Lu-164 were determined in a Doppler-shift attenuation-method experiment. From fractional Doppler shifts and line shapes, average transition quadrupole moments, Q(t) = 8.2(-0.6)(+1.0) b and 7.1(-0.6)(+0.5) 1), were deduced for one of the bands in Lu-163 OX -0.6 and Lu-164, respectively. These values are much larger than the quadrupole moment of the normal-deformed yrast band in Yb-163, Q(t) = 4.9(-0.4)(+1.34) b, that was also determined in this experiment. Comparison to cranking calculations indicates that both superdeformed bands correspond to a local potential energy minimum with a pronounced triaxiality, gamma similar to 20degrees.
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| 7. |
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