| 1. |
- Smith, J. F., et al.
(author)
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Excited states and signature inversion in Cs-116
- 2006
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 74:3, s. 034310-
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Journal article (peer-reviewed)abstract
- Excited states have been observed for the first time in the very neutron-deficient, odd-odd nucleus, Cs-116(55)61. The assignment to Cs-116 has been made by the detection of gamma rays in coincidence with evaporated charged particles and with evaporation residues. The observed states form a rotational band which has been assigned to the nu(h(11/2)) circle times pi(h(11/2)) configuration. Tentative spin assignments have been made on the basis of systematic comparisons with neighboring cesium isotopes. A low-spin signature inversion is observed in the band at a rotational frequency of about 0.23 MeV/h. The observed signature inversions in the odd-odd Cs116-126 isotopes have been compared with the results of extended total Routhian surface calculations, in which signature inversion arises as a consequence of quadrupole-pairing correlations and triaxial deformation. As previously shown for some of the odd-odd A similar or equal to 120 isotopes, the calculations reproduce the signature inversions reasonably well.
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| 2. |
- Wilson, A. N., et al.
(author)
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High-spin structures and alignment properties in Ce-126
- 2001
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 6305:5
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Journal article (peer-reviewed)abstract
- Excited states in Ce-126 have been observed with the GAMMASPHERE gamma -ray detector array, used in conjunction with the MICROBALL charged-particle detector. The reaction Zn-64(Zn-64, xpn alpha) (beam energy 260 MeV) was used to populate a wide range of nuclei in the neutron-deficient region with A approximate to 120. Ce-126 was populated via the 2p evaporation channel. The three previously observed bands have been extended to higher spins and some other structures have been identified. The yrast band shows evidence of a delayed neutron alignment occurring at a rotational frequency omega approximate to0.5 MeV/(h) over bar as observed in the neighboring odd-A nucleus Pr-127. One of the two excited bands shows evidence for a similar crossing at a slightly lower frequency and also exhibits a sudden gain in alignment at omega =0.57 MeV/(h) over bar. The third band may involve the coupling of a gamma -vibrational state. All three rotational bands are discussed in terms of standard and extended cranked shell model calculations.
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| 3. |
- Evans, A. O., et al.
(author)
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Magnetic properties of deformed dipole bands in Te-110,Te-112
- 2006
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In: Physica Scripta. - 0031-8949. ; T125, s. 192-193
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Journal article (peer-reviewed)abstract
- A lifetime analysis using the Doppler-shift attenuation method has been performed on the Tellurium isotopes Te-110,Te-112. The experiment was performed using the Gammasphere array in conjunction with the MICROBALL charged-particle detector. Three strongly coupled bands were previously established in Te-110,Te-112 which were observed up to unusually high spins. In the current experiment, it has been possible to extract lifetime measurements using a Doppler broadened lineshape analysis on one of the Delta I = 1 band structures in Te-110. In contrast to similar Delta I = 1 structures in other nuclei in this mass region, the extracted B(M1) values did not rapidly decrease with increasing angular momentum. Instead, the strongly coupled band in Te-110 represents a deformed 1p-1h structure, rather than a weakly deformed structure showing the shears mechanism.
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| 4. |
- LaFosse, D. R., et al.
(author)
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Collective structures and band termination in 107Sb
- 2000
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In: Physical Review C - Nuclear Physics. - 0556-2813. ; 62:1
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Journal article (peer-reviewed)abstract
- High-spin states in the near proton-dripline nucleus 107Sb have been identified, and collectivity in this nucleus has been observed for the first time in the form of two rotational bands. One of the observed rotational structures is a ΔI = 1 band, and is interpreted as based on a π(g9/2)-1 ⊗ π(g7/2d5/2)2 proton configuration. A second structure has ΔI = 2 character, and is explained as being based on a πh11/2⊗[π(g9/2)-2 ⊗ π(g7/2d5/2)2] proton configuration through comparison with cranked Nilsson-Strutinsky model calculations. The calculations predict that this band terminates at a spin of 79/2 (Latin small letter h with stroke).
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| 5. |
- Lane, G. J., et al.
(author)
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Identification of excited states in doubly odd [Formula Presented]Sb : Smooth band termination
- 1997
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In: Physical Review C - Nuclear Physics. - 0556-2813. ; 55:5, s. 2127-2131
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Journal article (peer-reviewed)abstract
- Excited states in [Formula Presented]Sb have been identified for the first time in a series of [Formula Presented]-spectroscopy experiments using both thin and backed targets, including neutron-fold and recoil-mass measurements to provide unambiguous channel identification. The three decoupled intruder bands observed in [Formula Presented]Sb are based upon configurations involving 2p-2h excitations across the [Formula Presented] shell gap and show the features of smooth band termination. The yrast intruder band, which has been connected to the low-spin levels, is tentatively identified up to its predicted termination at [Formula Presented]. Excellent agreement with configuration-dependent cranked Nilsson-Strutinsky calculations is obtained for the high-spin states near termination.
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| 6. |
- Naguleswaran, S., et al.
(author)
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Magnetic and intruder rotational bands in In-113
- 2005
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 72:4, s. 044304-
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Journal article (peer-reviewed)abstract
- Excited states in In-113 were populated via the reactions Mo-100(O-18,p4n)In-113 and Pd-110(Li-7,4n)In-113. The two known Delta J=2 intruder bands, based on the pi g(7/2)circle times d(5/2) and pi h(11/2) orbitals, have been extended by 8h to spins (49/2(+))h and (55/2(-))h, respectively. The previous finding of three sequences of Delta J=1 gamma-ray transitions has been confirmed. A self-consistent cranked shell-model calculation gives a good description of the contrasting alignment patterns of the two Delta J=2 intruder bands. The intruder bands, the known sequences of M1 transitions, and spherical levels together represent a coexistence of three different excitation modes in this nucleus.
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| 7. |
- Paul, E. S., et al.
(author)
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Smooth terminating bands in Te-112: Particle-hole induced collectivity
- 2007
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 75:1
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Journal article (peer-reviewed)abstract
- The Gammasphere spectrometer, in conjunction with the Microball charged-particle array, was used to investigate high-spin states in Te-112 via Ni-58(Ni-58, 4p gamma) reactions at 240 and 250 MeV. Several smooth terminating bands were established, and lifetime measurements were performed for the strongest one using the Doppler-shift attenuation method. Results obtained in the spin range 18-32h yield a transition quadrupole moment of 4.0 +/- 0.5eb, which corresponds to a quadrupole deformation epsilon(2)=0.26 +/- 0.03; this value is significantly larger than the ground-state deformation of tellurium isotopes. It was also possible to extract a transition quadrupole moment for the yrast band in Xe-114, produced via the 58Ni (58Ni, 2p gamma) reaction. A value of 3.0 +/- 0.5eb was found in the spin range 16-24h, which corresponds to a quadrupole deformation epsilon(2)=0.19 +/- 0.03. Cranked Nilsson-Strutinsky calculations are used to interpret the results.
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| 8. |
- Starosta, K., et al.
(author)
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Smooth band termination at high spin in 113I
- 2001
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In: Physical Review C - Nuclear Physics. - 0556-2813. ; 64:1, s. 143041-1430419
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Journal article (peer-reviewed)abstract
- The 113I nucleus has been studied using the 58Ni(58Ni,3p) reaction at 250 MeV with the Gammasphere/ Microball facility. Gamma-ray three-and four-fold data gated by charged particle combinations were analyzed. Multipolarities of the γ rays were assigned following the angular correlation measurements. The present study is focused on the high spin properties, where the structure is dominated by 2p-2h excitations across the Z=50 gap. Ten decoupled bands showing the features of smooth band termination were observed; three of those bands are linked to known low-spin states, which allows the identification of configurations by direct comparisons with configuration-dependent cranked Nilsson-Strutinsky calculations. The yrast band, which was linked along with the signature partner, was followed up to (101/2+) and ℏω∼1.3 MeV. The other linked band was a negative-parity band observed up to (95/2-). Tentative configurations for the unlinked bands are discussed. Comparisons with the theoretical results suggest that the band built on a configuration involving the neutron i13/2 intruder orbital originating from the N=6 harmonic oscillator subshell was observed in this experiment.
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| 9. |
- Smith, J. F., et al.
(author)
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Identification of excited states in 119Ba
- 2000
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In: Physical Review C - Nuclear Physics. - 0556-2813. ; 61:4
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Journal article (peer-reviewed)abstract
- Excited states have been identified in the very neutron-deficient 119Ba nucleus. Two bands have been observed, which are likely to be based on h11/2 and (g7/2d5/2) neutron orbitals. Despite this being the first observation of excited states in 119Ba, the bands extend to (75/2)ℏ and (79/2)ℏ, respectively. The bands have been assigned to 119Ba using gamma-recoil and gamma-x-ray coincidences. Several quasiparticle alignments have been identified, involving neutron (h11/2)2 and proton (h11/2)2 aligned configurations. Furthermore, the bands show features which are reasonably consistent with smooth band termination at high spin. Theoretical results for 119Ba are discussed within the framework of cranked Woods-Saxon and Nilsson-Strutinsky calculations.
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| 10. |
- Thorslund, I., et al.
(author)
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Intruder bands in Te114 : Smooth band termination
- 1995
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In: Physical Review C. - 0556-2813. ; 52:6, s. 2839-2843
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Journal article (peer-reviewed)abstract
- The nucleus Te114 has been studied in heavy-ion -ray spectroscopy experiments performed with the early implementation of the GAMMASPHERE multidetector array. Three rotational intruder bands have been observed up to high spins. The yrast band, involving the 4p2h (h11/2)2(g7/2)2(g9/2)-2 proton configuration, reaches I=48Latin small letter h with stroke at an excitation energy of 30.3 MeV, the highest observed spin connected by rays in this mass region. The band properties are interpreted in the framework of smooth band termination.
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| 11. |
- Paul, E. S., et al.
(author)
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High-spin yrast states in the gamma-soft nuclei Pr-135 and Ce-134
- 2011
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 84:4
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Journal article (peer-reviewed)abstract
- High-spin states have been studied in Pr-135(59), populated through the Cd-116(Na-23,4n) reaction at 115 MeV, using the Gammasphere gamma-ray spectrometer. The negative-parity yrast band has been significantly extended to spin similar to 45 (h) over bar and excitation energy 21.5 MeV, showing evidence for several rotational alignments. The positive-parity yrast band of Ce-135(58), populated through the p4n channel of this reaction, was also populated to spin similar to 38 (h) over bar and excitation energy 18 MeV. Cranking calculations indicate that these nuclei are soft with respect to the triaxiality parameter gamma and that several competing nuclear shapes occur at high spin.
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