High-spin yrast and non-yrast bands in 176Os, 178Os and 180Os

Dracoulis, George; Fahlander, C.; Fewell, M.P.

doi:10.1016/0375-9474(82)90080-x

Cited by 75 publications

(18 citation statements)

References 50 publications

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“…In principle, it is possible that the K π = 5 − band could contain octupole admixtures, which would cause a lower spin for the (unobserved) band head, and a corresponding decrease in the K value associated with the band. Such behavior has been observed in the Os and Hf isotopes [26,27], where it has been proposed that the low-lying octupole vibration is crossed at moderate frequency by a shape-driving, two-quasiproton excitation. In fact, a J π = 3 − state has been proposed in 128 Xe [3] at an excitation energy of 2138.6 keV, but it is not observed in the current work.…”

Section: -7mentioning

confidence: 71%

Shape-driving effects in the triaxial nucleus,Xe128

et al. 2006

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An extended decay scheme for 128 Xe has been constructed by using data from the 124 Sn( 9 Be, 5n) 128 Xe reaction at a beam energy of 58 MeV. Bands have been identified as being built on several intrinsic states, including a proposed 9/2 − [514] ⊗ 1/2 + [400] two-quasineutron configuration that forms the K π = 5 − intrinsic state at 2228 keV, and on a previously assigned K π = 8 − intrinsic state at 2786 keV. A half-life of 73(3) ns has been measured for the latter. Theoretical calculations have been performed by using the configuration-constrained blocking method based on a nonaxial Woods-Saxon potential. Large γ deformation and γ softness are predicted for the ground state and the K π = 5 − intrinsic state, whereas a nearly axially symmetric shape is predicted for the K π = 8 − two-quasiparticle configuration. The low value of the hindrance factor for the E1 transition depopulating the K π = 8 − intrinsic state is discussed in the context of analogous transitions in neighbouring N = 74 isotones.

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Section: -7mentioning

confidence: 71%

Shape-driving effects in the triaxial nucleus,Xe128

et al. 2006

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“…A value of V gs ≈ 20 keV is quoted for 172 Hf based on two-band mixing calculations fitted to excitation energies of the yrast band members only [25]. In 176 Os, a similar exercise was used to quote rough limits of 40-60 keV for V gs [26]. Subsequent analysis of the same data in 176 Os, using three-band mixing calculations incorporating a third deformed intruder band, yields values of V gs that vary from 29 [27] to 174 keV [28].…”

Section: K π Configurationmentioning

confidence: 99%

High-Kisomers and rotational structures inW174

et al. 2006

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High-spin states in 174 W (Z = 74) have been populated using the reaction 128 Te( 50 Ti, 4n) 174 W at beam energies of 215 and 225 MeV. The Gammasphere array was used to detect the γ rays emitted by the evaporation residues. Four previously known collective band structures have been extended, and 16 new rotational sequences observed. Two are built upon isomeric states, one corresponding to a two-quasiparticle K = 8 isomer, the other to a four-quasiparticle K = 12 isomer, with the latter exhibiting strong K-violating K = 12 decays to the ground state band. Nucleonic configurations for the two-and four-quasiparticle excitations are proposed, and Woods-Saxon cranking calculations are presented to understand the rotational structures. Decay mechanisms of multi-quasiparticle K isomers are discussed in terms of the prevalent phenomenological models, with special emphasis on γ -tunneling calculations. Surprisingly, the latter underpredict the decay hindrance for the K = 12 isomer by three orders of magnitude, unlike all other isomer decays in this mass region.

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“…While the former transitions could a priori be expected to dominate (because the larger energy is favored), it is sometimes the case for octupole vibrations that J ÿ 1 ! J deexcitations gather more of the strength [40,41].…”

mentioning

confidence: 99%

Octupole Vibration in SuperdeformedD66152y86

et al. 2002

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Nine transitions of dipole character have been identified linking an excited superdeformed (SD) band in 152Dy to the yrast SD band. As a result, the excitation energy of the lowest level in the excited SD band has been measured to be 14 238 keV. This corresponds to a 1.3 MeV excitation above the SD ground state. The levels in this band have tentatively been determined to be of negative parity and odd spin. The measured properties are consistent with an interpretation in terms of a rotational band built on a collective octupole vibration.

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High-spin yrast and non-yrast bands in 176Os, 178Os and 180Os

Cited by 75 publications

References 50 publications

Shape-driving effects in the triaxial nucleus,Xe128

Shape-driving effects in the triaxial nucleus,Xe128

High-Kisomers and rotational structures inW174

Octupole Vibration in SuperdeformedD66152y86

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