| 1. |
- Bargholtz, Chr., et al.
(författare)
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The WASA detector facility at CELSIUS
- 2008
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 594:3, s. 339-350
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Tidskriftsartikel (refereegranskat)abstract
- The WASA 4 pi multidetector system, aimed at investigating light meson production in light ion collisions and eta meson rare decays at the CELSIUS storage ring in Uppsala is presented. A unique feature of the system is the use of hydrogen pellets as internal targets for the first time. A detailed description of the design, together with the anticipated and achieved performance parameters are given. (C) 2008 Elsevier B.V. All rights reserved.
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| 2. |
- Yamamoto, A., et al.
(författare)
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The ATLAS central solenoid
- 2008
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 584:1, s. 53-74
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Tidskriftsartikel (refereegranskat)abstract
- The ATLAS detector at the CERN LHC is equipped with a superconducting magnet system consisting of three large toroids and a solenoid. The 2.3 m diameter, 5.3 m long solenoid is located at the heart of the experiment where it provides a 2 T field for spectrometry of the particles emanating from the interaction of the counter-rotating beams of hadrons. As the electromagnetic calorimeter of the experiment is situated outside the solenoid, the coil must be as transparent as possible to traversing particles. The magnet, which was designed at KEK, incorporates progress in technology coming from the development of previous solenoids of this type, in particular that of a new type of reinforced superconductor addressing the requirement of transparency. Special attention has been paid to ensuring reliability and ease of operation of the magnet, through the application of sufficiently conservative guidelines for the mechanical and electrical design, stringent testing during manufacture, and a comprehensive commissioning program. This report gives an overview of the design, manufacture, test, installation and commissioning of the ATLAS central solenoid.
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| 3. |
- Adolph, C, et al.
(författare)
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Measurement of the eta -> 3 pi(0) Dalitz plot distribution with the WASA detector at COSY
- 2009
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 677:1-2, s. 24-29
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Tidskriftsartikel (refereegranskat)abstract
- In the first production run of the WASA experiment at COSY, the eta decay into three neutral pions was measured in proton-proton interactions at a proton beam kinetic energy of 1.4 GeV. The Dalitz plot of the three pious was Studied using 1.2 x 10(5) fully reconstructed events. and the quadratic slope parameter alpha was determined to be -0.027 +/- 0.008(stat) +/- 0.005(syst). The result is consistent with previous measurements and further corroborates the importance of pion-pion final state interactions. (C) 2009 Elsevier B.V. All rights reserved.
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| 4. |
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| 5. |
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| 6. |
- Linz, Bodo, et al.
(författare)
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An African origin for the intimate association between humans and Helicobacter pylori
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 445:7130, s. 915-918
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Tidskriftsartikel (refereegranskat)abstract
- Infection of the stomach by Helicobacter pylori is ubiquitous among humans. However, although H. pylori strains from different geographic areas are associated with clear phylogeographic differentiation(1-4), the age of an association between these bacteria with humans remains highly controversial(5,6). Here we show, using sequences from a large data set of bacterial strains that, as in humans, genetic diversity in H. pylori decreases with geographic distance from east Africa, the cradle of modern humans. We also observe similar clines of genetic isolation by distance (IBD) for both H. pylori and its human host at a worldwide scale. Like humans, simulations indicate that H. pylori seems to have spread from east Africa around 58,000 yr ago. Even at more restricted geographic scales, where IBD tends to become blurred, principal component clines in H. pylori from Europe strongly resemble the classical clines for Europeans described by Cavalli-Sforza and colleagues(7). Taken together, our results establish that anatomically modern humans were already infected by H. pylori before their migrations from Africa and demonstrate that H. pylori has remained intimately associated with their human host populations ever since.
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| 7. |
- Zou, Y., et al.
(författare)
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Study of vacancy decays in the L-shell photoionization of barium in the excitation energy range of 5.6-30 keV: from L-2 edge to energy high above the thresholds of double L-vacancy production
- 2006
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 39:22, s. 4775-4788
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Tidskriftsartikel (refereegranskat)abstract
- Photoinduced Ba L x-rays were measured, in the excitation energy range of 5.6-30 keV, by using high-brilliance undulator radiation. The obtained intensity ratios, the excitation-energy independent L beta(4)/L beta(3), L eta/L beta(1), L iota/L alpha(1,2), L beta(6)/ L alpha(1,2) and L beta(2,15)/L alpha(1,2) as well as the excitation- energy dependent L beta(1)/L alpha(1,2), L beta(3)/L alpha(1,2) and L beta(3)/L beta(1), were compared with theoretical calculations, in which the calculations were performed by applying various subsets of the L subshell fluorescence yields and Coster-Kronig yields. Deviations of the theoretical calculations from the experimental results call on improvements in theory for the emission rates. We have also surveyed the L alpha(1,2) related x-ray hypersatellite lines in the photoinduced Ba L x-ray spectrum.
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