| 1. |
- Schael, S., et al.
(författare)
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Electroweak measurements in electron positron collisions at W-boson-pair energies at LEP
- 2013
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 532:4, s. 119-244
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Forskningsöversikt (refereegranskat)abstract
- Electroweak measurements performed with data taken at the electron positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3 fb(-1) collected by the four LEP experiments ALEPH, DELPHI, 13 and OPAL, at centre-of-mass energies ranging from 130 GeV to 209 GeV. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose Einstein correlations between the two W decay systems arising in WW production, are searched for and upper limits on the strength of possible effects are obtained. The data are used to determine fundamental properties of the W boson and the electroweak theory. Among others, the mass and width of the W boson, m(w) and Gamma(w), the branching fraction of W decays to hadrons, B(W -> had), and the trilinear gauge-boson self-couplings g(1)(Z), K-gamma and lambda(gamma), are determined to be: m(w) = 80.376 +/- 0.033 GeV Gamma(w) = 2.195 +/- 0.083 GeV B(W -> had) = 67.41 +/- 0.27% g(1)(Z) = 0.984(-0.020)(+0.018) K-gamma - 0.982 +/- 0.042 lambda(gamma) = 0.022 +/- 0.019. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Bécoulet, A., et al.
(författare)
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Science and technology research and development in support to ITER and the Broader Approach at CEA
- 2013
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 53:10
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Tidskriftsartikel (refereegranskat)abstract
- In parallel to the direct contribution to the procurement phase of ITER and Broader Approach, CEA has initiated research & development programmes, accompanied by experiments together with a significant modelling effort, aimed at ensuring robust operation, plasma performance, as well as mitigating the risks of the procurement phase. This overview reports the latest progress in both fusion science and technology including many areas, namely the mitigation of superconducting magnet quenches, disruption-generated runaway electrons, edge-localized modes (ELMs), the development of imaging surveillance, and heating and current drive systems for steady-state operation. The WEST (W Environment for Steady-state Tokamaks) project, turning Tore Supra into an actively cooled W-divertor platform open to the ITER partners and industries, is presented.
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| 3. |
- 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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| 4. |
- Callegaro, Sara, et al.
(författare)
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Upper and lower crust recycling in the source of CAMP basaltic dykes from southeastern North America
- 2013
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Ingår i: Earth and Planetary Science Letters. - 0012-821X .- 1385-013X. ; 376, s. 186-199
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Tidskriftsartikel (refereegranskat)abstract
- The densest dykes swarm of the Central Atlantic magmatic province (CAMP) occur in southeastern North America (SENA) and were intruded between 202 and 195 Ma during Pangea break-up. New combined geochemical data (major and trace elements, Sr–Nd–Pb–Os isotopes) constrain the mantle source of these magmatic bodies and their evolution path. While Sr–Nd isotopic compositions for SENA rocks (87Sr/86Sr200Ma 0.70438–0.70880 and 143Nd/144Nd200Ma 0.51251–0.51204) fall within the low-Ti CAMP field, Pb–Pb isotopes (206Pb/204Pb200Ma 17.46–18.85, 207Pb/204Pb200Ma 15.54–15.65, 208Pb/204Pb200Ma 37.47–38.76) are peculiar to this area of the CAMP and cover a considerable span of compositions, especially in 206Pb/204Pb200Ma. Given the generally unradiogenic Os isotopic compositions (187Os/188Os200Ma 0.127–0.144) observed and the lack of correlation between these and other geochemical markers, crustal contamination during the evolution of SENA dykes must have been limited (less than 10%). Thus the isotopic variation is interpreted to reside primarily within the mantle source. These observations, coupled with typical continental signatures in trace elements (positive anomaly in Pb and negative anomalies in Ti and Nb), require another means of conveying a continental flavor to these magmas, which is here hypothesized to be the shallow recycling within the upper mantle of subducted lower and upper crustal materials. Pseudo-ternary mixing models show that a maximum of 10% recycled crust is enough to explain their trace element patterns as well as their isotopic heterogeneity. Looking at the larger picture of the origin of the CAMP, the thermal contribution of a mantle plume cannot be ruled out due to the relatively high mantle potential temperatures (1430–1480 °C) calculated for high-Fo SENA olivines. Nevertheless, our results suggest that the chemical involvement of a mantle plume is negligible (less than 5%) if either a C- or an EM-flavored plume is considered. Rather, the possibility of a PREMA-flavored mantle plume, enriched by 5–20% recycled crustal material, remains a possible, though less plausible, source for these tholeiites.
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| 5. |
- Cawood, P. A., et al.
(författare)
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Orogenesis without collision : Stabilizing the Terra Australis accretionary orogen, eastern Australia
- 2011
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Ingår i: Geological Society of America Bulletin. - 0016-7606 .- 1943-2674. ; 123:11-12, s. 2240-2255
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Tidskriftsartikel (refereegranskat)abstract
- The Neoproterozoic to end-Paleozoic Terra Australis orogen extended along the Gondwana margin of the paleo–Pacific Ocean, and it now provides a detailed record of orogenic activity and continental stabilization within an ongoing convergent, accretionary plate margin. New geochronological data from end-Paleozoic plutonic and volcanic rocks associated with the Gondwanide orogeny in the New England region of eastern Australia, integrated with information on the nature and timing of associated sedimentation, deformation, and metamorphism, allow resolution of a high-fidelity record of orogenesis.At the end of the Carboniferous, around 305 Ma, convergent margin magmatism, which had been active along the western margin of the New England region, terminated and was followed by a short pulse of regional compressional deformation and metamorphism, marking the commencement of the Tablelands phase of Gondwanide orogenesis. Deformation was almost immediately followed by the onset of clastic sedimentation and local calc-alkaline volcanism, dated at 293 Ma, in the extensional Barnard Basin. Emplacement of the two New England S-type granitic suites, the Bundarra and the Hillgrove suites, along with localized high-temperature, low-pressure metamorphism, was essentially contemporaneous, ranging in age from 296 to 288 Ma, and overlapped in time with I-type magmatism and the switch from regional compression to extension and Barnard Basin rifting.The Hunter-Bowen phase of the Gondwanide orogeny commenced with contractional deformation, resulting in termination of sedimentation in the Barnard Basin and regional deformation and metamorphism across New England and into the Sydney and Gunnedah basins to the west at around 265–260 Ma. Contractional loading of the Sydney and Gunnedah basins resulted in their conversion from extensional to foreland basins, which received ongoing pulses of sediment from the New England orogenic welt until 230 Ma. The Hunter-Bowen phase was associated with widespread I-type plutonism and volcanic activity in New England that ceased around 230 Ma, marking the termination of Gondwanide orogenesis.Orogenesis occurred in an evolving convergent plate-margin setting. S- and I-type magmatic activity ranging in age from ca. 300 to 230 Ma represents a stepping out of arc magmatism from the western margin of New England (prior to 305 Ma) into the preexisting arc-trench gap. There is no evidence that deformation was related to the collision of the convergent margin with a major lithospheric mass, and the widespread development of extensional basins in the eastern third of Australia in the Early Permian indicates control by phenomena acting on a continental scale, probably changing plate kinematics associated with the amalgamation of Pangea.
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| 6. |
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| 7. |
- Cawood, P. A., et al.
(författare)
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Provenance of the Highland Border Complex : constraints on Laurentian margin accretion in the Scottish Caledonides
- 2012
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Ingår i: Journal of the Geological Society. - : Geological Society of London. - 0016-7649 .- 2041-479X. ; 169:5
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Tidskriftsartikel (refereegranskat)abstract
- Contrasting tectonic models for the Highland Border Complex in the Scottish Caledonides view it either as part of the rifted Laurentian margin of the Iapetus Ocean or as an oceanic terrane. Detrital zircon data from sandstones of the complex yield age peaks at 2.8–2.6, 1.3 and 1.1–1.0 Ga and minor peaks at c. 1.7–1.9 Ga. These characteristics compare closely with those of the upper Dalradian Supergroup of the adjacent Grampian terrane, and with the record of eastern Laurentia. The data are also consistent with the Laurentian provenance indicated by palaeontological evidence from the complex, and field evidence for continuity with the Dalradian Supergroup. Detrital ages for the Cambrian Salterella Grit of the Caledonian foreland compare with those for approximately age-equivalent sandstones from the Highland Border Complex. Both were contemporaneous with the regressive Hawke Bay event, accounting for similarities in provenance, and further linking the Highland Border Complex to Laurentia. The Grampian terrane was being uplifted and shedding detritus throughout the Ordovician and Silurian. The absence of this event from the detrital zircon records of either the Midland Valley or Southern Upland terranes suggests that these blocks cannot have been in their current location relative to the Grampian terrane before the end of the Silurian.Supplementary material: The complete analytical dataset and cathodoluminescence images are available at http://www.geolsoc.org.uk/SUP18531.
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| 8. |
- Grange, M., et al.
(författare)
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Plume–Lithosphere Interaction during Migration of Cretaceous Alkaline Magmatism in SW Portugal : Evidence from U–Pb Ages and Pb–Sr–Hf Isotopes
- 2010
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Ingår i: Journal of Petrology. - : Oxford University Press (OUP). - 0022-3530 .- 1460-2415. ; 51:5, s. 1143-1170
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Tidskriftsartikel (refereegranskat)abstract
- Large massifs of alkaline rocks are exposed along ∼250 km of the Atlantic coast of Portugal. Their origin is still poorly understood, including the precise timing of their emplacement and their relationships with the well-constrained alkaline magmatic rocks that occur 200–1000 km offshore. To elucidate the precise timing and origin of the alkaline magmatism in this region, magmatic rocks from the three major alkaline massifs (Sintra, Sines, and Monchique) and an isolated diorite intrusion (Ribamar, north of Sintra) have been dated by the U–Pb method on titanite and zircon and characterized based on their Pb, Sr, and Hf isotopic compositions obtained on feldspar and zircon. From north to south, the resulting ages are: 88·3 ± 0·5 Ma (95% confidence level) for Ribamar, 83·4 ± 0·7, 82·0 ± 0·7, 81·7 ± 0·4, and 80·1 ± 1·0 Ma for the Sintra complex, 77·2 ± 0·6, 77·2 ± 0·4, and 76·1 ± 1·3 Ma for the Sines massif, and 70·0 ± 2·9 and 68·8 ± 1·0 Ma for the Monchique complex. Initial isotopic compositions of Pb in feldspars are in the range of 18·522–19·299 for 206Pb/204Pb, 15·555–16·007 for 207Pb/204Pb, and 38·480–39·330 for 208Pb/204Pb. Initial 87Sr/86Sr of feldspars varies between 0·70274 and 0·70481 and initial Hf isotope ratios yield εHfi values between +3·7 and +9·6. These results, together with major, trace, and rare earth element analyses, show that the ages, (207Pb/204Pb)i, and (87Sr/86Sr)i increase northward, whereas the alkaline affinity, (206Pb/204Pb)i, and εHfi increase southward, substantiating a north–south trend of geochemical and age variation. The isotopic composition of the studied rocks can be explained by partial melting of a sub-lithospheric mantle source with an enriched DMM (Depleted MORB Mantle) signature and subsequent contamination by the metasomatized Iberian subcontinental lithospheric mantle (SCLM). The north–south age trend is in agreement with the motion of the Iberian plate between 88 and 60 Ma. The spatial and temporal variations in the isotopic signatures are explained by differences in the contribution of the two source components. The sub-lithospheric mantle-derived magmas are more contaminated by the SCLM in the northern part of the alignment, compared with the southern part of the studied region, where the rocks have isotopic signatures closer to those of enriched sub-lithospheric mantle. Our data are incorporated into a geodynamical model that explains the overall distribution of alkaline magmatism in this part of the eastern Central Atlantic, and provide new constraints on the occurrence of alkaline magmatism along the Iberian margin and the NW African plate. The spatial distribution of the magmatism is directly correlated with the motion of the Iberian plate above a deep-rooted thermal anomaly (mantle plume) that has caused magmatism since the Cretaceous.
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| 9. |
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| 10. |
- Kuhn, Annegret, et al.
(författare)
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Photoprovocation in Cutaneous Lupus Erythematosus : A Multicenter Study Evaluating a Standardized Protocol
- 2011
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Ingår i: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 131:8, s. 1622-1630
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Tidskriftsartikel (refereegranskat)abstract
- Photosensitivity is an important and distinguishing sign in various subtypes of cutaneous lupus erythematosus (CLE); however, it remains poorly defined. The purpose of this study was to evaluate whether standardized photoprovocation is a reproducible method to assess photosensitivity in subjects with CLE. A total of 47 subjects with CLE (subacute cutaneous lupus erythematosus (SCLE), n = 14; discoid lupus erythematosus (DLE), n = 20; lupus erythematosus tumidus (LET), n = 13) and 13 healthy volunteers underwent photoprovocation at seven European sites. Of these, 22 (47%) subjects (57% SCLE, 35% DLE, and 54% LET) and none of the healthy volunteers developed photoprovoked lesions according to clinical analysis. Of these 22 subjects, 19 (86%) developed lesions that were histopathologically confirmed as specific for lupus erythematosus (LE). In CLE subjects who developed UV-induced lesions, 86% had Fitzpatrick's phototypes I or II, and the mean minimal erythema dose (MED) was significantly lower compared with subjects without UV-induced lesions (P = 0.004). No significant differences in photoprovocation results were observed between study sites. Safety parameters showed no clinically meaningful differences between CLE subjects and healthy volunteers after photoprovocation. In conclusion, a standardized, safe, and reproducible protocol for photoprovocation using UVA and UVB radiation induced skin lesions in approximately half of all CLE subjects and showed comparable results across multiple sites. This method may therefore be used for future diagnostic testing and clinical trials.
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