| 1. |
- Danilin, B.V., et al.
(författare)
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Three-body continuum energy correlations in Borromean halo nuclei. III. Short-range external fields
- 2007
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 76, s. 064612-
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Tidskriftsartikel (refereegranskat)abstract
- Energy correlations in transition from the bound state to the three-body continuum of Borromean halo nuclei are considered. A core+n+n three-body cluster model which reproduces the experimentally known properties of 6He and 11Li has been used to study the low-lying resonances and soft modes. An analysis of the correlated responses in 6He shows that in the case of the narrow 2+ resonance the transition energy correlations are the same as in the intrinsic correlated structure in 3->3 scattering. They differ significantly for wide second 2+ and first 1+ resonances, and also for the soft dipole and monopole modes, where due to the transition operators, the intertwinning of the ground state and the three-body continuum plays a significant role.
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| 2. |
- Diget, C. A., et al.
(författare)
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Breakup channels for C-12 triple-alpha continuum states
- 2009
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 80:3
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Tidskriftsartikel (refereegranskat)abstract
- The triple-alpha-particle breakup of states in the triple-alpha continuum of C-12 has been investigated by way of coincident detection of all three alpha particles of the breakup. The states have been fed in the beta decay of N-12 and B-12, and the alpha particles measured using a setup that covers all of the triple-alpha phase space. Contributions from the breakup through the Be-8(0(+)) ground state as well as other channels-interpreted as breakup through excited energies in Be-8-have been identified. Spins and parities of C-12 triple-alpha continuum states are deduced from the measured phase-space distributions for breakup through Be-8 above the ground state by comparison to a fully symmetrized sequential R-matrix description of the breakup. At around 10 MeV in C-12, the breakup is found to be dominated by 0(+) strength breaking up through the ghost of the Be-8(0(+)) ground state with L = 0 angular momentum between the first emitted alpha particle and the intermediate Be-8 nucleus. For C-12 energies above the 12.7 MeV 1(+) state, however, L = 2 breakup of a C-12 2(+) state through the Be-8(2(+)) excited state dominates. Furthermore, the possibility of a 2(+) excited state in the 9-12 MeV region of C-12 is investigated.
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| 3. |
- Dohmann, H., et al.
(författare)
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The (d,2He) reaction on Mo96 and the double-β decay matrix elements for Zr96
- 2008
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 78:4
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Tidskriftsartikel (refereegranskat)abstract
- The 96Mo(d,2He)96Nb charge-exchange reaction was investigated at an incident energy of Ed=183.5 MeV. An excitation-energy resolution of 110 keV was achieved. The experiment was performed at KVI, Groningen, using the magnetic spectrometer BBS at three angular positions: 0°,2.5°, and 6°. We found that below 6 MeV almost the entire Gamow-Teller (GT+) strength is concentrated in a single state at 0.69 MeV excitation energy. As Mo96 is the daughter of the ?? decay nucleus Zr96, the present result provides information about the nuclear matrix elements active in the 2??? decay of Zr96.
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| 4. |
- Forssen, Christian, 1974, et al.
(författare)
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Charge radii and electromagnetic moments of Li and Be isotopes from the ab initio no-core shell model
- 2009
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 79:2, s. 021303(R)-
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Tidskriftsartikel (refereegranskat)abstract
- Recently, charge radii and ground-state electromagnetic moments of Li and Be isotopes were measured precisely. We have performed large-scale ab initio no-core shell model calculations for these isotopes using high-precision nucleon-nucleon potentials. The isotopic trends of our computed charge radii and quadrupole and magnetic-dipole moments are in good agreement with experimental results with the exception of the 11Li charge radius. The magnetic moments are in particular well described, whereas the absolute magnitudes of the quadrupole moments are about 10% too small. The small magnitude of the 6Li quadrupole moment is reproduced, and with the CD-Bonn NN potential, also its correct sign.
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| 5. |
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| 6. |
- Grewe, E. W., et al.
(författare)
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Studies on the double-beta decay nucleus Zn-64 using the (d,He-2) reaction
- 2008
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 77:6
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Tidskriftsartikel (refereegranskat)abstract
- The (d,He-2) charge-exchange reaction on the double-beta decay (beta beta) nucleus Zn-64 has been studied at an incident energy of 183 MeV. The two protons in the S-1(0) state (indicated as He-2) were both momentum analyzed and detected simultaneously by the BBS magnetic spectrometer and its position-sensitive detector. He-2 spectra with a resolution of about 115 keV (FWHM) have been obtained allowing identification of many levels in the residual nucleus Cu-64 with high precision. Zn-64 is one of the rare cases undergoing a beta beta decay in beta(+) direction. In the experiment presented here, Gamow-Teller (GT(+)) transition strengths have been extracted. Together with the GT(-) transition strengths from Ni-64(He-3,t) data to the same intermediate nucleus Cu-64, the nuclear matrix elements of the beta beta decay of Zn-64 have been evaluated. Finally, the GT(+/-) distributions are compared with shell-model calculations and a critical assessment is given of the various residual interactions presently employed for the pf shell.
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| 7. |
- Grigorenko, L. V., et al.
(författare)
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Three-body decay of Be-6
- 2009
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 80:3
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Tidskriftsartikel (refereegranskat)abstract
- Three-body correlations for the ground-state decay of the lightest two-proton emitter Be-6 are studied both theoretically and experimentally. Theoretical studies are performed in a three-body hyperspherical-harmonics cluster model. In the experimental studies, the ground state of Be-6 was formed following the alpha decay of a C-10 beam inelastically excited through interactions with Be and C targets. Excellent agreement between theory and experiment is obtained demonstrating the existence of complicated correlation patterns that can elucidate the structure of Be-6 and, possibly, of the A = 6 isobars.
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| 8. |
- Grigorenko, L. V., et al.
(författare)
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Two-proton radioactivity and three-body decay. III. Integral formulas for decay widths in a simplified semianalytical approach
- 2007
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 76:1, s. Article Number: 014008-
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Tidskriftsartikel (refereegranskat)abstract
- Three-body decays of resonant states are studied using integral formulas for decay widths. The theoretical approach with a simplified Hamiltonian allows semianalytical treatment of the problem. The model is applied to decays of the first excited 3/2- state of 17Ne and the 3/2- ground state of 45Fe. The convergence of the three-body hyperspherical model calculations to the exact result for widths and energy distributions are studied. The theoretical results for 17Ne and 45Fe are updated, and uncertainties of the derived values are discussed in detail. Correlations for the decay of the 17Ne 3/2- state are also studied.
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| 9. |
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| 10. |
- Hyldegaard, S., et al.
(författare)
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Branching ratios in the beta decays of N-12 and B-12
- 2009
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 80:4
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Tidskriftsartikel (refereegranskat)abstract
- Absolute branching ratios to unbound states in C-12 populated in the beta decays of N-12 and B-12 are reported. Clean sources of N-12 and B-12 were obtained using the isotope separation on-line (ISOL) method. The relative branching ratios to the different populated states were extracted using single-alpha as well as complete kinematics triple-alpha spectra. These two largely independent methods give consistent results. Absolute normalization is achieved via the precisely known absolute branching ratio to the bound 4.44 MeV state in C-12. The extracted branching ratios to the unbound states are a factor of three more precise than previous measurements. Branching ratios in the decay of Na-20 are also extracted and used to check the results.
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| 11. |
- Knudsen, H. H., et al.
(författare)
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Beta-decay of 13O
- 2005
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 72:4, s. 044312-
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Tidskriftsartikel (refereegranskat)abstract
- The beta decay of O-13 has been studied at the IGISOL facility of the Jyvaskyla accelerator centre (Finland). By developing a low-energy isotope-separated beam of O-13 and using a modern segmented charged-particle detector array an improved measurement of the delayed proton spectrum was possible. Protons with energy up to more than 12 MeV are measured and the corresponding log(ft) values extracted. A revised decay scheme is constructed. The connection to molecular states and the shell model is discussed.
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| 12. |
- Mancusi, Davide, 1980, et al.
(författare)
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Stability of Nuclei in Peripheral Collisions in the JAERI Quantum Molecular Dynamics Model
- 2009
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 79:1
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Tidskriftsartikel (refereegranskat)abstract
- The JAERI quantum molecular dynamics (JQMD) model has been successfully used for a long time now to describe many different aspects of nuclear reactions in a unified way. In some cases, however, the JQMD model cannot produce consistent results: First, it lacks a fully relativistically covariant approach to the problem of molecular dynamics; second, the quantum-mechanical ground state of nuclei cannot be faithfully reproduced in a semiclassical framework. Therefore, we introduce R-JQMD, an improved version of JQMD that also features a new ground-state initialization algorithm for nuclei. We compare the structure of the two codes and discuss whether R-JQMD can be adjusted to improve JQMD's agreement with measured heavy-ion fragmentation cross sections.
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| 13. |
- Platter, Lucas, 1976
(författare)
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Three-nucleon system at next-to-next-to-leading order
- 2006
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 74:3
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Tidskriftsartikel (refereegranskat)abstract
- We calculate higher order corrections for the three-nucleon system up to next-to-next-to-leading within an effective field theory with contact interactions alone. We employ a subtraction formalism previously developed and for which it has been shown that no new three-body force counterterm is needed for complete renormalization up to this order. We give results for the neutron-deuteron phaseshifts and the triton binding energy. Our results are in very good agreement with experimental results and calculations using realistic nucleon-nucleon potentials.
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| 14. |
- Toshito, T., et al.
(författare)
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Measurements of projectile-like Be-8 and B-9 production in 200-400 MeV/nucleon C-12 on water
- 2008
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 78:6, s. 4-
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the production of the projectile-like fragments Be-8 and B-9 produced in interactions of 200 to 400 MeV/nucleon carbon ions with water, using emulsion detectors. In this Brief Report we present the first published production cross section of the projectile-like fragment B-9 in the energy region above 100 MeV/nucleon. The measured production cross sections of these nuclides were compared to calculations using a semiempirical model. We found that the measured cross sections deviate from the calculated values by a factor up to about six. This information is of importance for benchmarking and improving heavy ion nuclear reaction models.
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| 15. |
- Toshito, T., et al.
(författare)
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Measurements of total and partial charge-changing cross sections for 200-to 400-MeV/nucleon C-12 on water and polycarbonate
- 2007
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 75:5, s. 8-
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Tidskriftsartikel (refereegranskat)abstract
- We have studied charged nuclear fragments produced by 200- to 400-MeV/nucleon carbon ions, interacting with water and polycarbonate, using a newly developed emulsion detector. Total and partial charge-changing cross sections for the production of B, Be, and Li fragments were measured and compared with both previously published measurements and model predictions. This study is of importance for validating and improving carbon-ion therapy treatment planning systems and for estimating the radiological risks for personnel on space missions, because carbon is a significant component of galactic cosmic rays.
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| 16. |
- Fissum, Kevin
(författare)
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Proton elastic form factor ratios to Q^2 = 1.5 GeV^2 by polarization transfer
- 2005
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Ingår i: Physical Review C: covering nuclear physics. - 2469-9985. ; 71, s. 069902-069902
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Tidskriftsartikel (refereegranskat)abstract
- This paper was published online on 20 May 2005 without several of the authors’ corrections incorporated. Equation (13) has been replaced. The captions of Figs. 16–18 have also been replaced. Typographical errors on pages 4, 6, 14, 15, 18, 19, 22, and 24 have all been corrected. The paper has been corrected as of 8 June 2005. The text is correct in the printed version of the journal.
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| 17. |
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