| 1. |
- Adlarson, Patrik, et al.
(författare)
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Cross section ratio and angular distributions of the reaction p + d -> He-3 + eta at 48.8MeV and 59.8MeV excess energy
- 2014
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 50:6, s. 100-
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Tidskriftsartikel (refereegranskat)abstract
- We present new data for angular distributions and on the cross section ratio of the p+d -> He-3+eta reaction at excess energies of Q - 48.8MeV and Q - 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Julich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval.
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| 2. |
- Benedikt, M., et al.
(författare)
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Conceptual design report for a Beta-Beam facility
- 2011
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 47:2
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Forskningsöversikt (refereegranskat)abstract
- The Beta-Beam is a concept of large-scale facility that aims at providing pure electronic neutrino and antineutrino beams for the measurement of v(e) -> v(mu) oscillations. Beta-decaying nuclides are produced in large amounts in a facility of the scale of EURISOL, and are then post-accelerated and stored at large gamma in a racetrack decay ring. We present here a conceptual design of the accelerator chain of a Beta-Beam based at CERN.
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| 3. |
- Bijnens, Johan, et al.
(författare)
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Chiral symmetry and charmonium decays to two pseudoscalars
- 2011
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 47:11
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Tidskriftsartikel (refereegranskat)abstract
- We apply hard pion Chiral Perturbation Theory to charmonium decays to pi pi, KK and eta eta. We first discuss why we expect to be able to provide results for the chiral logarithms in chi(c0) and chi(c2) decays to two pseudoscalars while for the decays from J/psi, psi(nS) and chi(c1) no simple prediction is possible. The leading chiral logarithm turns out to be absent for chi(c0), chi(c2) -> PP. This result is true for all fully chiral singlet states of spin zero and two.
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| 4. |
- David, J. C., et al.
(författare)
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Modeling astatine production in liquid lead-bismuth spallation targets
- 2013
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 49:3
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Tidskriftsartikel (refereegranskat)abstract
- Astatine isotopes can be produced in liquid lead-bismuth eutectic targets through proton-induced double charge exchange reactions on bismuth or in secondary helium-induced interactions. Models implemented into the most common high-energy transport codes generally have difficulties to correctly estimate their production yields as was shown recently by the ISOLDE Collaboration, which measured release rates from a lead-bismuth target irradiated by 1.4 and 1 GeV protons. In this paper, we first study the capability of the new version of the Liege intranuclear cascade model, INCL4.6, coupled to the de-excitation code ABLA07 to predict the different elementary reactions involved in the production of such isotopes through a detailed comparison of the model with the available experimental data from the literature. Although a few remaining deficiencies are identified, very satisfactory results are found, thanks in particular to improvements brought recently on the treatment of low-energy helium-induced reactions. The implementation of the models into MCNPX allows identifying the respective contributions of the different possible reaction channels in the ISOLDE case. Finally, the full simulation of the ISOLDE experiment is performed, taking into account the likely rather long diffusion time from the target, and compared with the measured diffusion rates for the different astatine isotopes, at the two studied energies, 1.4 and 1 GeV. The shape of the isotopic distribution is perfectly reproduced as well as the absolute release rates, assuming in the calculation a diffusion time between 5 and 10 hours. This work finally shows that our model, thanks to the attention paid to the emission of high-energy clusters and to low-energy cluster induced reactions, can be safely used within MCNPX to predict isotopes with a charge larger than that of the target by two units in spallation targets, and, probably, more generally to isotopes created in secondary reactions induced by composite particles.
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| 5. |
- DiJulio, Douglas, et al.
(författare)
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Coulomb excitation of Sn-107
- 2012
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 48:7
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Tidskriftsartikel (refereegranskat)abstract
- The radioactive isotope Sn-107 was studied using Coulomb excitation at the REX-ISOLDE facility at CERN. This is the lightest odd-Sn nucleus examined using this technique. The reduced transition probability of the lowest-lying 3/2(+) state was measured and is compared to shell-model predictions based on several sets of single-neutron energies relative to Sn-100. Similar to the transition probabilities for the 2(+) states in the neutron-deficient even-even Sn nuclei, the measured value is underestimated by shell-model calculations. Part of the strength may be recovered by considering the ordering of the d(5/2) and g(7/2) single-neutron states.
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| 6. |
- DiJulio, Douglas, et al.
(författare)
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Electromagnetic properties of vibrational bands in Er-170
- 2011
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 47:2, s. 25-
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Tidskriftsartikel (refereegranskat)abstract
- Excited states of the nucleus Er-170 have been studied by Coulomb excitation using the GASP gamma-ray detector system at the Laboratori Nazionali di Legnaro. The ground-state band along with a low-lying K-pi = 0(+) band and gamma-vibrational band were populated during the experiment. Based on the measured gamma-ray yields, a set of interband and intraband matrix elements has been extracted using the Coulomb excitation code GOSIA. The resulting E2 matrix elements are compared to collective model predictions.
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| 7. |
- Droese, C., et al.
(författare)
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High-precision Mass Measurements of 203-207Rn and 213Ra with SHIPTRAP
- 2013
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 49:1, s. 13-19
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Tidskriftsartikel (refereegranskat)abstract
- The masses of the nuclides Rn203-207 and Ra-213 were measured directly for the first time with the Penning-trap mass spectrometer SHIPTRAP at GSI Darmstadt. The results confirm the previously determined mass values. The mass uncertainties for Rn-205 and Ra-213 were significantly reduced. The results are relevant for the investigation of the nuclear shell structure between N = 82 and N = 126. As an indicator of structural changes the two-neutron separation energies S-2n(Z, N) have been studied.
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| 8. |
- Ekström, Andreas, et al.
(författare)
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Coulomb excitation of the odd-odd isotopes In-106,In-108
- 2010
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 44:3, s. 355-361
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Tidskriftsartikel (refereegranskat)abstract
- The low-lying states in the odd-odd and unstable isotopes In-106,In-108 have been Coulomb excited from the ground state and the first excited isomeric state at the REX-ISOLDE facility at CERN. With the additional data provided here the pi g(9/2)(-1) circle times nu d(5/2) and pi g(9/2)(-1) circle times nu g7/2 multiplets have been re-analyzed and are modified compared to previous results. The observed gamma-ray de-excitation patterns were interpreted within a shell model calculation based on a realistic effective interaction. The agreement between theory and experiment is satisfactory and the calculations reproduce the observed differences in the excitation pattern of the two isotopes. The calculations exclude a 6(+) ground state in In-106. This is in agreement with the conclusions drawn using other techniques. Furthermore, based on the experimental results, it is also concluded that the ordering of the isomeric and ground state in In-108 is inverted compared to the shell model prediction. Limits on B(E2) values have been extracted where possible. A previously unknown low-lying state at 367 keV in In-106 is also reported.
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| 9. |
- Erni, W., et al.
(författare)
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Technical design report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
- 2013
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 49:2
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Tidskriftsartikel (refereegranskat)abstract
- This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.
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| 10. |
- Hagen, P., et al.
(författare)
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Charge form factors of two-neutron halo nuclei in halo EFT
- 2013
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-601X .- 1434-6001. ; 49:9, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- We set up a formalism to calculate the charge form factors of two-neutron halo nuclei with S-wave neutron-core interactions in the framework of the halo effective field theory. The method is applied to some known and suspected halo nuclei. In particular, we calculate the form factors and charge radii relative to the core to leading order in the halo EFT and compare to experiments where they are available. Moreover, we investigate the general dependence of the charge radius on the core mass and the one-and two-neutron separation energies.
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