1. |
- Jeppesen, H. B., et al.
(author)
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Multi-quasiparticle states in (256)Rf
- 2009
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 79:3, s. 031303-
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Journal article (peer-reviewed)abstract
- Excited states in (256)Rf were populated via the Pb-208(Ti-50,2n) fusion-evaporation reaction. Delayed gamma-ray and electron decay spectroscopy was performed and three isomeric states in (256)Rf have been identified. A fourth low-energy nonyrast state was identified from the gamma-ray decay of one of the higher lying isomers. The states are interpreted as multi-quasiparticle excitations.
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2. |
- Petri, M., et al.
(author)
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Structure of C-16: Testing shell model and ab initio approaches
- 2012
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In: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 86:4, s. Art. no. 044329-
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Journal article (peer-reviewed)abstract
- Excited states in C-16 were populated via the Be-9(N-17,C-16+gamma)X one-proton knockout reaction. The lifetime of the 2(1)(+) state in C-16 was measured using the recoil distance method. The extracted lifetime of tau(+)(21) = 11.4(-0.9)(+0.8)(stat) +/- 0.7(syst(B rho))(-1.5)(+0.0)(syst(feeding)) ps yields a deduced B(E2;2(1)(+) -> 0(1)(+)) = 4.21(-0.26)(+0.34)(stat)(-0.24)(+0.28)(syst(B rho))(-0.00)(+0.64)(syst(feeding)) e(2)fm(4) value in good agreement with a previous measurement. The one-proton knockout cross section is used to extract the proton amplitude of the C-16 2(1)(+) state, which confirms the neutron dominant character of this state. Gamma-ray branching ratios between the 2(2)(+) state and the 2(1)(+) and ground states were also determined. The results are compared with p-sd shell model and no-core shell model (with NN and NN + NNN) calculations. The inclusion of three-body forces are essential in order for the no-core shell model calculations to reproduce the experimental findings on the gamma-ray branching ratios.
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3. |
- Cooper, M. W., et al.
(author)
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New γ transitions in 27Na from 14C on 14C
- 2001
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In: Nuclear Physics A. - 0375-9474. ; 682:1-4, s. 131-135
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Journal article (peer-reviewed)abstract
- The neutron rich 27Na was studied at Florida State University using the 14C(14C,p) reaction at 22 MeV. The 14C target was 0.28 mg/cm2 thick. γ-γ and particle-γ, coincidences were measured using 2 four-crystal clover detectors, 7 Compton-suppressed HPGe detectors, and a particle detector telescope at 0°. The 1757, 1823, and 2219 keV transitions are likely yrast transitions in 27Na. Based on systematics of neighboring nuclei, the first two lines probably arise from the decays of the 7/2+ and 9/2+ states. The results will be discussed in terms of both the shell model and the cranked Nilsson-Strutinsky rotational model.
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4. |
- Tabor, S. L., et al.
(author)
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Structure of neutron-rich s-d shell nuclei
- 2002
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In: Physics of Atomic Nuclei. - : Pleiades Publishing Ltd. - 1063-7788 .- 1562-692X. ; 65:4, s. 713-719
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Journal article (peer-reviewed)abstract
- States in neutron-rich s-d shell nuclei were populated in the reaction of a 14C beam at Elab = 22 MeV on a 14C target. Coincidences between γ rays and either other γ rays or light charged particles were measured. γ rays in coincidence with protons established levels at 66.8, 1730, 1823, and 2219 keV in 27Na. The states are compared with calculations based on the s-d shell model and the cranked Nilsson-Strutinsky model. A number of levels in 24Ne were observed in both α-γ and α-γ-γ coincidences and are compared with shell-model calculations.
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5. |
- Wiedeking, M., et al.
(author)
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Transition strengths and band terminations in 86Zr
- 2003
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In: Physical Review C - Nuclear Physics. - 0556-2813. ; 67, s. 1-034320
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Journal article (peer-reviewed)abstract
- High angular momentum states in 86Zr were populated through the 58Ni(32S,4p) reaction at 135 MeV using the 88-In. Cyclotron at Lawrence Berkeley National Laboratory. Recoiling 86Zr nuclei were stopped in a thick Ta backing. Prompt multi-γ coincidences with evaporated charged particles were detected using the full array of GAMMASPHERE and the MICROBALL. Mean lifetimes of 36 levels in 86Zr were measured using the Doppler-shift attenuation method. Transition quadrupole moments Qt were found in the range of about 0.3-1.5 e b in the positive-parity bands. The negative-parity bands show Qt values from about 0.25 to 1.2 e b. In the yrast positive-parity band, a sharp drop in collectivity approaching the 30+ state supports the interpretation of band termination in this configuration. Decreasing Qt values approaching the 24+ and 27- states also provide an indication of terminating structures.
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