1. |
- Svensson, C. E., et al.
(författare)
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Collective rotational motion in the N=Z nucleus 36Ar
- 2001
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Ingår i: Nuclear Physics A. - 0375-9474. ; 682:1-4, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- A superdeformed rotational band has been identified in the N = Z nucleus 36Ar, firmly linked to known low-spin states, and observed to its high-spin termination at Iπ = 16+. Lifetime measurements by the Doppler shift attenuation method establish a large low-spin deformation (β2 ≈ 0.46) and a decrease in the collectivity as the band approaches termination. Comparisons with cranked Nilsson-Strutinsky and large-scale spherical shell model calculations lead to a consistent description of the band based on a configuration in which four particles are promoted to the pf shell. With two major shells active for both protons and neutrons, yet a valence space dimension small enough to be approached from the shell model perspective, this band offers an excellent opportunity to investigate the microscopic structure of collective rotational motion in nuclei.
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2. |
- Svensson, C. E., et al.
(författare)
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Superdeformation in the N = z Nucleus 36Ar : Experimental, deformed mean field, and spherical shell model descriptions
- 2000
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Ingår i: Physical Review Letters. - 0031-9007. ; 85:13, s. 2693-2696
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Tidskriftsartikel (refereegranskat)abstract
- A superdeformed rotational band has been identified in 36Ar, linked to known low-spin states, and observed to its high-spin termination at Iπ = 16+. Cranked Nilsson-Strutinsky and spherical shell model calculations assign the band to a configuration in which four pf-shell orbitals are occupied, leading to a low-spin deformation β2 ≈ 0.45. Two major shells are active for both protons and neutrons, yet the valence space remains small enough to be confronted with the shell model. This band thus provides an ideal case to study the microscopic structure of collective rotational motion.
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3. |
- Ward, D., et al.
(författare)
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Band Structure of 68Ge
- 2001
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 63:1
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Tidskriftsartikel (refereegranskat)abstract
- The nucleus Ge-68 has been studied by gamma-ray spectroscopy following its population at high spin in the reaction Ca-40(S-32,4p) Ge-68. The reaction channel was selected with the Microball array and gamma rays were detected with the Gammasphere array. The level scheme is very complex, reflecting the many different, and presumably mixed, excitation modes in this nucleus. Nevertheless, there appear to be some simplifications in the spin range above 18 (h) over bar where we have identified a superdeformed band and several terminating bands. The results are compared with a cranked Nilsson-Strutinsky model without pairing.
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4. |
- Karlgren, Daniel, et al.
(författare)
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High-angular-momentum structures in Zn-64
- 2004
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 69, s. 1-034330
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Tidskriftsartikel (refereegranskat)abstract
- High-angular-momentum states in Zn-64 were populated in the Ca-40(Si-28,4p) reaction at a beam energy of 122 MeV. Evaporated, light, charged particles were identified by the Microball, while gamma rays were detected using the Gammasphere array. The main focus of this paper is on two strongly coupled, collective bands. The yrast band, which was previously known, has been linked to lower-lying states establishing the excitation energies and angular momenta of in-band states for the first time. The newly identified excited band decays to the yrast band but firm angular-momentum assignments could not be made. In order to interpret these structures cranked-Nilsson-Strutinsky calculations have been performed. The calculations have been extended to account for the distribution of nucleons within a configuration. The yrast collective band is interpreted as based on the pi(f(7/2))(-1)(p(3/2)f(5/2))(2)(g(9/2))(1)nu(p(3/2)f(5/2))(4)(g(9/2))(2) configuration. There are several possible interpretations of the second band but it is difficult to distinguish between the different possibilities.
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5. |
- Svensson, C. E., et al.
(författare)
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Lifetimes of superdeformed rotational states in 36Ar
- 2001
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Ingår i: Physical Review C - Nuclear Physics. - 0556-2813. ; 63:6, s. 613011-613015
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Tidskriftsartikel (refereegranskat)abstract
- Lifetimes have been measured in a superdeformed rotational band recently identified in the N = Z nucleus 36Ar. A large low-spin quadrupole deformation (β2=0.46±0.03) is confirmed and a decrease in the collectivity is observed as the high-spin band termination at Iπ=16+ is approached. Detailed comparisons of the experimental B(E2) values with the results of cranked Nilsson-Strutinsky and large-scale (s1/2d3/2)-pf spherical shell model calculations indicate the need for a more refined treatment of transition matrix elements close to termination in the former, and the inclusion of the complete sd-pf model space in the latter description of this highly-collective rotational band.
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6. |
- Svensson, C. E., et al.
(författare)
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Lifetimes of superdeformed rotational states in [Formula Presented]
- 2001
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Ingår i: Physical Review C - Nuclear Physics. - 0556-2813. ; 63:6, s. 5-5
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Tidskriftsartikel (refereegranskat)abstract
- Lifetimes have been measured in a superdeformed rotational band recently identified in the [Formula Presented] nucleus [Formula Presented] A large low-spin quadrupole deformation [Formula Presented] is confirmed and a decrease in the collectivity is observed as the high-spin band termination at [Formula Presented] is approached. Detailed comparisons of the experimental [Formula Presented] values with the results of cranked Nilsson-Strutinsky and large-scale [Formula Presented] spherical shell model calculations indicate the need for a more refined treatment of transition matrix elements close to termination in the former, and the inclusion of the complete [Formula Presented] model space in the latter description of this highly-collective rotational band.
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7. |
- Ideguchi, E., et al.
(författare)
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Orbifold projection in supersymmetric QCD at N(f) ≤ N(c)
- 2000
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 492:3-4, s. 369-375
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Tidskriftsartikel (refereegranskat)abstract
- Supersymmetric orbifold projection of N = 1 SQCD with relatively small number of flavors (N(f) ≤ N(c)) is considered. The purpose is to check whether orbifolding commutes with the infrared limit. On the one hand, one considers the orbifold projection of SQCD and obtains the low-energy description of the resulting theory. On the other hand, one starts with the low-energy effective theory of the original SQCD, and only then performs orbifolding. It is shown that at finite N(c) the two low-energy theories obtained in these ways are different. However, in the case of stabilized run-away vacuum these two theories are shown to coincide in the large N(c) limit. In the case of quantum modified moduli space, topological solitons carrying baryonic charges are present in the orbifolded low-energy theory. These solitons may restore the correspondence between the two theories provided that the soliton mass tends to zero in the large N(c) limit. (C) 2000 Elsevier Science B.V.
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8. |
- Kelsall, N. S., et al.
(författare)
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Testing mean-field models near the N=Z line : gamma-ray spectroscopy of the T-z=1/2 nucleus Kr-73
- 2002
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 65:4
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Tidskriftsartikel (refereegranskat)abstract
- Excited states in the N=Z+1 nucleus Kr-73 have been investigated using the Ca-40(Ar-36,2pn) and Ca-40(Ca-40,alpha2pn) reactions at 145 and 160 MeV, respectively. gamma rays were detected using the Gammasphere array and events were recorded in coincidence with charged-particle and neutron detectors. The three previously observed bands were extended to high spin, and a new unfavored positive-parity band has been observed. The alignment characteristics and decay properties of the bands are all consistent with large-deformation prolate rotation, with no clear evidence for oblate bands or shape coexistence. This is quite different from neighboring Kr-72,Kr-74, indicating a strong shape-stabilizing role for the valence neutron. The experimental results are compared to extended total Routhian surface, cranked Nilsson Strutinsky, and cranked relativistic mean-field calculations. The results suggest that the paired calculations lack some important physics. Neutron-proton correlations may be the missing ingredient. There is also evidence for an unusual band crossing in the negative-parity bands, which may indicate the presence of T=0 pairing correlations. At high spin all the models can reproduce the experimental data.
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9. |
- Lipoglavsek, M., et al.
(författare)
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First Observation of Excitation Across the 100Sn Core
- 2001
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Ingår i: Nuclear Physics, Section A. - 0375-9474. ; 682, s. 399-403
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Tidskriftsartikel (refereegranskat)abstract
- Excited states of nuclei near the doubly-magic nucleus Sn-100 were studied with the Ni-58+Cr-50 reaction. The experimental setup consisted of the GAMMASPHERE array augmented with light charged-particle and neutron detectors. Excited states were identified for the first time in the proton emitting nucleus Sb-105. Excitations across the N=Z=50 doubly closed shell were observed in Cd-99 and In-101. Some results of large-scale shell-model calculations are discussed.
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10. |
- Wilson, A. N., et al.
(författare)
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Magnetic dipole bands in 190Hg : First evidence of excitations across the Z = 82 sub-shell in Hg nuclei
- 2001
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 505:1-4, s. 6-14
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Tidskriftsartikel (refereegranskat)abstract
- An experiment aimed at studying high-spin states in 190Hg was performed with the Eurogam II array. The data have revealed the presence of cascades of magnetic dipole transitions with some unexpected properties. Unlike the MI bands previously observed in the heavier Hg isotopes, these structures have extremely large B(M1)/B(E2) ratios, The observation of a third dipole band with much lower B(M1)/B(E2) values in the same spin/excitation energy regime suggests that the bands may represent configurations occurring in different minima in the potential energy surface. Configuration-dependent Cranked Nilsson-Strutinsky calculations predict the presence of a minimum in the nuclear potential energy surface at a deformation of ε ≅ 0.2, γ ≅ -90°, occurring when a proton is excited across the Z = 82 shell-gap into an h9/2 orbital. It is suggested that the bands exhibiting anomalously large B(M1)/B(E2) ratios may be associated with this minimum.
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11. |
- Ekman, Jörgen, et al.
(författare)
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The A=51 Mirror Nuclei 51Fe and 51Mn
- 2000
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - 1434-6001. ; 9, s. 13-17
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Tidskriftsartikel (refereegranskat)abstract
- Eighteen previously unknown gamma -ray transitions were identified in the T-z = -1/2 nucleus Fe-51 following the fusion-evaporation reaction S-32(Si-28,2 alpha 1n)Fe-51. The lever scheme reaches the fully aligned I-pi = 27/2(-) terminating state of the five holes in the f(7/2) shell. The 17/2(-) state was found to be isomeric, and the lifetime was measured to be 2.87 ns. The mirror symmetry of Fe-51 and Mn-51 is discussed, and the level scheme of Fe-51 is compared to shell-model calculations.
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12. |
- Fischer, S. M., et al.
(författare)
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Alignment delays in the N = Z nuclei Kr-72, Sr-76, and Zr-80
- 2001
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 8713:13
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Tidskriftsartikel (refereegranskat)abstract
- The ground state rotational bands of the N = Z nuclei Kr-72, Sr-76, and Zr-80 have been extended into the angular momentum region where rotation alignment of particles is normally expected. By measuring the moments of inertia of these bands we have observed a consistent increase in the rotational frequency required to start pair breaking, when compared to neighboring nuclei. Kr-72 shows the most marked effect. It has been widely suggested that these delayed alignments arise from np-pairing correlations. However, alignment frequencies are very sensitive to shape degrees of freedom and normal pairing, so the new experimental observations are still open to interpretation.
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13. |
- Ideguchi, Eiji, et al.
(författare)
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Superdeformation in 91Tc
- 2000
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 492:3-4, s. 245-253
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Tidskriftsartikel (refereegranskat)abstract
- A high-spin rotational band with 11 gamma -ray transitions has barn observed in Tc-91. The dynamical moment of inertia as well as the transition quadrupole moment of 8.1(-1.4)(+1.9) eb measured for this band show the characteristics of a superdeformed band. However, the shape is more elongated than in the neighbouring A = 80-90 superdeformed nuclei. Theoretical interpretations of the band within the cranked Strutinsky approach based on two different Woods-Saxon potential parameterisations are presented. Even though an unambiguous configuration assignment proved difficult, both calculations indicate a larger deformation and at least three additional high-N intruder orbitals occupied compared to the lighter SD nuclei. (C) 2000 Elsevier Science B.V. All rights reserved.
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14. |
- Ideguchi, E., et al.
(författare)
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Superdeformation in the Doubly Magic Nucleus 40Ca
- 2001
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Ingår i: Physical Review Letters. - 1079-7114. ; 87:22
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Tidskriftsartikel (refereegranskat)abstract
- A rotational band with seven gamma -ray transitions between states with spin 2 (h) over bar and 16 (h) over bar has been observed in the doubly magic, self-conjugate nucleus Ca-40(20)20. The measured transition quadrupole moment of 1.80(-0.29)(+0.39)eb indicates a superdeformed shape with a deformation beta (2) = 0.59(-0.07)(+0.11). The features of this band are explained by cranked relativistic mean field calculations to arise from an 8-particle 8-hole excitation.
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15. |
- Lipoglavsek, M, et al.
(författare)
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100Sn Core Excitations in 102In
- 2002
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 65:2
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Tidskriftsartikel (refereegranskat)abstract
- Nuclei in the vicinity of the doubly-magic Sn-100 nucleus have been studied, and an extended level scheme for In-102 has been established. The level structure comprises both the negative parity states involving the nuh(11/2) orbital, and levels due to the breakup of the doubly-magic Sn-100 core. Results of a large-scale shell model calculation, using realistic and empirical effective interactions with Sr-88 as a core, are in very good agreement with the experimental data.
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16. |
- Lipoglavsek, M, et al.
(författare)
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Breakup of the Doubly Magic 100Sn Core
- 2002
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 66:1
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Tidskriftsartikel (refereegranskat)abstract
- Level schemes of Cd-99(48)51 and In-101(49)52 nuclei have been extended to high spin. The breakup of the doubly magic Sn-100 core has been observed. Large-scale shell model calculations based on realistic nucleon-nucleon interactions are in good agreement with the experimental data. These results provide a reliable basis to predict nuclear structure properties in Sn-100 and its neighbors. For example, the size of the N=50 shell gap and the energy of the first excited state in Sn-101 have been deduced.
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17. |
- Lipoglavsek, M, et al.
(författare)
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Excited States of the Proton Emitter 105Sb
- 2002
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 65:5
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Tidskriftsartikel (refereegranskat)abstract
- Excited states in the proton emitter Sb-105 have been investigated for the first time. The nucleus was populated in the reaction Cr-50(Ni-58,1p2n). The GAMMASPHERE Ge-detector array was used together with Microball and the Neutron Shell for selection of the reaction channel. The experimental level scheme agrees well with results of a shell model calculation that uses realistic effective interactions derived from the CD-Bonn nucleon-nucleon interaction and Sn-100 as a closed-shell core.
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18. |
- Ma, W. C., et al.
(författare)
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Competition between terminating and collective structures above spin 40ℏ in 154Dy
- 2002
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Ingår i: Physical Review C - Nuclear Physics. - 0556-2813. ; 65, s. 1-034312
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in 154Dy were studied with the Gammasphere spectrometer using the 36S(122Sn,4n) reaction. Band terminating states were identified in the spin range I= (36-48)ℏ, and were found to compete with collective rotational cascades up to the highest observed spins. Several "sidebands" feeding the terminating structures were identified as well. A band dominated by M1 transitions was observed to terminate at Iπ = 42-. The data are interpreted within the framework of configuration-dependent cranked Nilsson-Strutinsky calculations without pairing.
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19. |
- Reviol, W., et al.
(författare)
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Rotational Bands Near 56Ni
- 2001
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Ingår i: Nuclear Physics, Section A. - 0375-9474. ; 682, s. 28-34
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Tidskriftsartikel (refereegranskat)abstract
- Rotational bands have been found in Co-57 and Ni-57, using Gammasphere in conjunction with the Microball and 30 neutron detectors. The bands in Co-57, extending the mass 60 region of deformation down to Z = 27, are signature partner sequences. The quadrupole moments and dynamic moments of inertia of the new bands in both nuclei are similar to those of rotational sequences in the neighboring nuclei. The high-spin structure of Co-57 is compared with Skyrme Hartree-Fock calculations.
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20. |
- Wilson, A. N., et al.
(författare)
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High-spin structures and alignment properties in Ce-126
- 2001
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 6305:5
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Tidskriftsartikel (refereegranskat)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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21. |
- Ideguchi, E, et al.
(författare)
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Superdeformation in the doubly magic nucleus Ca-40(20)20
- 2001
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Ingår i: PHYSICAL REVIEW LETTERS. - : AMERICAN PHYSICAL SOC, COLLEGE PK. - 0031-9007. ; 87:222501, s. 2501-
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Tidskriftsartikel (refereegranskat)abstract
- A rotational band with seven gamma -ray transitions between states with spin 2 (h) over bar and 16 (h) over bar has been observed in the doubly magic, self-conjugate nucleus Ca-40(20)20. The measured transition quadrupole moment of 1.80(-0.29)(+0.39)eb in
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22. |
- Kamali, A, et al.
(författare)
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Syndromic management of sexually-transmitted infections and behaviour change interventions on transmission of HIV-1 in rural Uganda : a community randomised trial.
- 2003
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 361:9358, s. 645-52
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Treatment of sexually-transmitted infections (STIs) and behavioural interventions are the main methods to prevent HIV in developing countries. We aimed to assess the effect of these interventions on incidence of HIV-1 and other sexually-transmitted infections. METHODS: We randomly allocated all adults living in 18 communities in rural Uganda to receive behavioural interventions alone (group A), behavioural and STI interventions (group B), or routine government health services and community development activities (group C). The primary outcome was HIV-1 incidence. Secondary outcomes were incidence of herpes simplex virus type 2 (HSV2) and active syphilis and prevalence of gonorrhoea, chlamydia, reported genital ulcers, reported genital discharge, and markers of behavioural change. Analysis was per protocol. FINDINGS: Compared with group C, the incidence rate ratio of HIV-1 was 0.94 (0.60-1.45, p=0.72) in group A and 1.00 (0.63-1.58, p=0.98) in group B, and the prevalence ratio of use of condoms with last casual partner was 1.12 (95% CI 0.99-1.25) in group A and 1.27 (1.02-1.56) in group B. Incidence of HSV2 was lower in group A than in group C (incidence rate ratio 0.65, 0.53-0.80) and incidence of active syphilis for high rapid plasma reagent test titre and prevalence of gonorrhoea were both lower in group B than in group C (active syphilis incidence rate ratio, 0.52, 0.27-0.98; gonorrhoea prevalence ratio, 0.25, 0.10-0.64). INTERPRETATION: The interventions we used were insufficient to reduce HIV-1 incidence in rural Uganda, where secular changes are occurring. More effective STI and behavioural interventions need to be developed for HIV control in mature epidemics.
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23. |
- Robinson, SD, et al.
(författare)
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High-spin structures and band termination effects in Cd-104
- 2002
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Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899. ; 28:6, s. 1415-1431
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in the neutron-deficient isotope Cd-104 were populated using the Cr-50(Ni-58,4p)Cd-104 reaction at a beam energy of 250 MeV The level scheme has been extended using triple gamma-ray coincidences to a spin of 29h and an excitation energy of 18.2 MeV. Several collective structures involving the excitation of h(11/2) neutrons have been observed to spins approaching 30h. The high-spin structure has been compared to the results of cranked Nilsson-Strutinsky calculations.
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24. |
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25. |
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26. |
- Carpenter, Lucy M, et al.
(författare)
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Independent effects of reported sexually transmitted infections and sexual behavior on HIV-1 prevalence among adult women, men, and teenagers in rural Uganda
- 2002
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Ingår i: Journal of Acquired Immune Deficiency Syndromes. - 1525-4135 .- 1944-7884. ; 29:2, s. 174-180
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess whether sexually transmitted infections (STIs) and sexual behavior are independently associated with HIV-1 among adult women, men, and teenagers in rural Uganda. DESIGN: Cross-sectional survey. METHODS: All adults (13 years and older) residing in 18 communities were invited to participate. HIV status was determined from serum samples and data collected during confidential interview. Independent effects of risk factors for HIV were estimated using adjusted odds ratios (ORs) with 95% confidence intervals (CIs) from logistic regression. RESULTS: Women reporting genital ulcers in the last 12 months were over twice as likely to be HIV positive after adjustment for sociodemographic factors and number of lifetime sexual partners (OR, 2.5; 95% CI, 1.9-3.4). Equivalent associations were stronger for men (OR, 3.2; 95% CI, 2.2-4.7) but weaker for teenagers (OR, 2.0, 95% CI, 0.5-8.7). Number of lifetime sexual partners was associated ( p <.05) with HIV status for women, men, and teenagers independently of reported genital ulcers. Teenagers reporting casual partners were over four times ( p <.001), and men reporting condom use almost twice ( p <.001), as likely to be HIV positive. Neither history of genital discharge nor other measures of sexual behavior were independently related to HIV status. CONCLUSION: Reported STIs and sexual behavior are independently associated with HIV in rural Uganda. Community-based interventions to reduce HIV should target both and should include teenagers.
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27. |
- Chiara, CJ, et al.
(författare)
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Transition Quadrupole Moments in the Superdeformed Band of 40Ca
- 2003
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 67:4
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Tidskriftsartikel (refereegranskat)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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28. |
- Ekman, Jörgen, et al.
(författare)
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Core Excited States in the A=51 Mirror Nuclei
- 2004
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 70:5
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Tidskriftsartikel (refereegranskat)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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29. |
- Ekman, Jörgen, et al.
(författare)
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Evidence for a 1g9/2 Rotational Band in 51Mn
- 2002
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 66:5, s. 513011-513015
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Tidskriftsartikel (refereegranskat)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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30. |
- Ekman, Jörgen, et al.
(författare)
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Gamma-ray Spectroscopy of Core-excited States in 51Mn
- 2004
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 70:1
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Tidskriftsartikel (refereegranskat)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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31. |
- Fricker-Gates, R A, et al.
(författare)
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EGF infusion stimulates the proliferation and migration of embryonic progenitor cells transplanted in the adult rat striatum
- 2000
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Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 165:2, s. 237-247
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Tidskriftsartikel (refereegranskat)abstract
- Immature progenitor cells (generated by in vitro propagation) may provide a useful alternative to primary cells (from dissected embryonic tissue) for transplantation if their migratory and proliferative and differentiation properties can be controlled and directed in vivo. In this study E15 murine EGF-responsive progenitor cells were transplanted to the striatum of adult rats. Simultaneously, these animals received continuous infusion of either epidermal growth factor (EGF) or vehicle, to the lateral ventricle, for 8 days. In animals that received EGF, the transplanted progenitors migrated toward the lateral ventricle and proliferated, as evidenced by bromodeoxyuridine incorporation. Progenitor cells transplanted to rats that received vehicle infusions showed neither of these responses. In all animals, transplanted progenitors expressed an immature astrocyte or oligodendrocyte phenotype, the majority of cells being astrocytes. We conclude that EGF stimulates the migration and proliferation of murine progenitor cells in vivo, either directly or indirectly, but does not influence their phenotypic differentiation.
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32. |
- Kamali, Anatoli, et al.
(författare)
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A community randomized controlled trial to investigate impact of improved STD management and behavioural interventions on HIV incidence in rural Masaka, Uganda : trial design, methods and baseline findings
- 2002
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Ingår i: Tropical medicine & international health. - : Wiley. - 1360-2276 .- 1365-3156. ; 7:12, s. 1053-1063
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To describe study design, methods and baseline findings of a behavioural intervention alone and in combination with improved management of sexually transmitted diseases (STDs) aimed at reducing HIV incidence and other STDs. DESIGN: A three-arm community randomized controlled trial (RCT) of 18 rural communities (approximately 96 000 adults) in SW Uganda. A standardized behavioural intervention was implemented in 12 communities (arms A and B) through community-based education, meetings and information leaflets. Six of these communities in addition received improved STD management through government and private health units (arm B). Arm C communities received routine government health services. Impact assessment was through three questionnaire and serological surveys of 750-1000 adults in each community at 18-24-month intervals. The primary outcome measure was HIV incidence and secondary measures were syphilis and herpes simplex virus type 2 incidence, prevalence of Neisseria gonorrhoea and Chlamydia trachomatis and sexual behaviour changes. RESULTS: Approximately 15 000 adults (72% of eligible population) were enrolled at baseline. HIV baseline prevalence rates were 9-10% in all arms and demographic and behavioural characteristics and STD prevalence were also similar. In intervention communities, there were 391 995 attendance at 81 502 activities (6.1 per target adult), 164 063 leaflets distributed (2.6 per person) and 1 586 270 condoms (16.5 condoms per adult). In the STD communities a total of 12 239 STD cases (65% women) were seen over a 5-year period (7.7 per 100 adults/year). CONCLUSION: This is the first community RCT of its type with a behavioural component. There is fair baseline comparability between study arms and process data suggest that interventions were adequately implemented.
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33. |
- Kelsall, NS, et al.
(författare)
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High-spin structure of N similar or equal to Z nuclei around the A=72 region
- 2004
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 20:1, s. 131-132
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states have been studied in Kr-72 and Br-72 using the Ca-40 + Ca-40 and Ar-36 + Ca-40 reactions at 164 and 145 MeV, respectively. The properties and configurations of the high-spin bands observed have been interpreted using impaired cranked Nilssou-Strutinsky (CNS), and for Kr-72, paired cranked relativistic Hartree-Bogoliubov (CRHB) calculations. In Kr-72 a new band has been identified that has the properties expected for the doubly aligned S-band configuration. In Br-72 the previously known bands have been extended to higher spin. This has lead to a re-interpretation of the configurations.
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34. |
- Kinsman, John, et al.
(författare)
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Evaluation of a comprehensive school-based AIDS education programme in rural Masaka, Uganda
- 2001
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Ingår i: Health Education Research. - : Oxford University Press (OUP). - 0268-1153 .- 1465-3648. ; 16:1, s. 85-100
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Tidskriftsartikel (refereegranskat)abstract
- A 19 activity extracurricular school-based AIDS education programme lasting 1 year was conducted in rural southwestern Uganda using specially trained teachers, and was evaluated using mutually supportive quantitative and qualitative methods. In total, 1274 students from 20 intervention schools and 803 students from 11 control schools completed questionnaires at baseline, and their classes were followed up. In addition, 93 students from five of the intervention schools participated in 12 focus group discussions. The programme had very little effect--seven of the nine key questionnaire variables showed no significant increase in score after the intervention. Data from the focus group discussions suggest that the programme was incompletely implemented, and that key activities such as condoms and the role-play exercises were covered only very superficially. The main reasons for this were a shortage of classroom time, as well as teachers' fear of controversy and the unfamiliar. We conclude that large-scale comprehensive school-based AIDS education programmes in sub-Saharan Africa may be more completely implemented if they are fully incorporated into national curricula and examined as part of life-skills education. This would require teachers to be trained in participatory teaching methods while still at training college.
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35. |
- Park, HI, et al.
(författare)
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Rotational structures near 40h in La-123
- 2003
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 68:4
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Tidskriftsartikel (refereegranskat)abstract
- The neutron-deficient nucleus La-123 was studied via the Mo-92(Ca-40,2ap) reaction at a beam energy of 184 MeV. Previously known bands were extended to a much higher spin, and in two cases the structures are now observed near 40 (h) over bar. In addition, three new sequences were identified and linked into previously known bands. The lowest (pi,alpha)=(+,-1/2) structure displays characteristics similar to those of analogous bands in La-127,La-129, which have been proposed as examples of smooth band termination. Cranked Nilsson-Strutinsky calculations were compared with the experimental data in La-123 to determine whether this band is approaching a terminating state as well.
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36. |
- Quigley, Maria A, et al.
(författare)
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The impact of attending a behavioural intervention on HIV incidence in Masaka, Uganda
- 2004
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Ingår i: AIDS. - : Ovid Technologies (Wolters Kluwer Health). - 0269-9370 .- 1473-5571. ; 18:15, s. 2055-2063
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Changing behaviour is an important method for preventing HIV infection. We examined why a community randomized trial of a behavioural intervention found no significant effect of this on HIV incidence in rural Uganda.DESIGN: An individual-level analysis of a community randomized trial.METHODS: All sexually active, initially HIV-seronegative individuals with data on sexual behaviour were included (1558 men and 1836 women). Uptake of the intervention was measured using self-reported attendance at meetings, videos, dramas, and interactions with community educators in the past year. Sexual behaviour was assessed using self-reported condom use and the number of sexual partners in the past year.RESULTS: Overall, 81% of individuals in the intervention communities and 9% in the comparison communities reported attending at least one of the intervention activities in the past year. Attendance was lower in women, in those aged 55 years or older, and in the widowed. There was a lower HIV incidence in those who reported attending at least one intervention activity compared with those who attended none, and in women this effect was statistically significant (in women, adjusted rate ratio 0.41, 95% CI 0.19-0.89, P = 0.024; in men, adjusted rate ratio 0.66, 95% CI 0.25-1.79, P = 0.42). Reported behaviour change did not differ markedly between those who did and did not report attending any intervention activities.CONCLUSION: Although the intervention had no significant benefit in the communities as a whole, it resulted in a reduced risk of HIV acquisition in women who attended it. The methodological implications for future trials are discussed.
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