| 1. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 3. |
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| 4. |
- Armesto, N., et al.
(författare)
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Heavy-ion collisions at the LHC-Last call for predictions
- 2008
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Ingår i: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 35:5, s. 054001-
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Forskningsöversikt (refereegranskat)abstract
- This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute 'Heavy Ion Collisions at the LHC - Last Call for Predictions', held from 14th May to 10th June 2007.
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| 5. |
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| 6. |
- Mason, P, et al.
(författare)
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Octupole signatures in Ba-124,Ba-125
- 2005
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Ingår i: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 31:10, s. S1729-S1733
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Tidskriftsartikel (refereegranskat)abstract
- The gamma decay of the nuclei Ba-121,Ba-125 has been investigated with the EUROBALL array, using the reaction Ni-64+Ni-64 at E-beam = 255 and 261 MeV. Six new E1 transitions have been found in the nucleus Ba-125, suggesting a significant role of octupole correlations in the origin of its parity doublets. The J(pi) = 3(-) level of the nucleus Ba-124 has been identified for the first time. Its excitation energy is in very good agreement with a prediction based on a microscopic model including octupole interactions.
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| 7. |
- Tinker, N. A., et al.
(författare)
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New DArT markers for oat provide enhanced map coverage and global germplasm characterization
- 2009
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 10:39
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Tidskriftsartikel (refereegranskat)abstract
- Background: Genomic discovery in oat and its application to oat improvement have been hindered by a lack of genetic markers common to different genetic maps, and by the difficulty of conducting whole-genome analysis using high-throughput markers. This study was intended to develop, characterize, and apply a large set of oat genetic markers based on Diversity Array Technology (DArT). Results: Approximately 19,000 genomic clones were isolated from complexity-reduced genomic representations of pooled DNA samples from 60 oat varieties of global origin. These were screened on three discovery arrays, with more than 2000 polymorphic markers being identified for use in this study, and approximately 2700 potentially polymorphic markers being identified for use in future studies. DNA sequence was obtained for 2573 clones and assembled into a non-redundant set of 1770 contigs and singletons. Of these, 705 showed highly significant (Expectation < 10E-10) BLAST similarity to gene sequences in public databases. Based on marker scores in 80 recombinant inbred lines, 1010 new DArT markers were used to saturate and improve the 'Kanota' x 'Ogle' genetic map. DArT markers provided map coverage approximately equivalent to existing markers. After binning markers from similar clones, as well as those with 99% scoring similarity, a set of 1295 non-redundant markers was used to analyze genetic diversity in 182 accessions of cultivated oat of worldwide origin. Results of this analysis confirmed that major clusters of oat diversity are related to spring vs. winter type, and to the presence of major breeding programs within geographical regions. Secondary clusters revealed groups that were often related to known pedigree structure. Conclusion: These markers will provide a solid basis for future efforts in genomic discovery, comparative mapping, and the generation of an oat consensus map. They will also provide new opportunities for directed breeding of superior oat varieties, and guidance in the maintenance of oat genetic diversity.
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| 8. |
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| 9. |
- Dénes, E., et al.
(författare)
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Radiation tolerance qualification tests of the final source interface unit for the ALICE experiment for the ALICE collaboration
- 2007
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Ingår i: Proceedings - 12th Workshop on Electronics for LHC and Future Experiments, LECC 2006. - : CERN. ; , s. 438-441
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Konferensbidrag (refereegranskat)abstract
- The ALICE Detector Data Link (DDL) is a high-speed optical link designed to interface the readout electronics of ALICE sub-detectors to the DAQ computers. The Source Interface Unit (SIU) of the DDL will operate in radiation environment. Previous tests showed that a configuration loss of SRAM-based FPGA devices may happen and the frequency of undetected data errors in the FPGA user memory area is also not acceptable. Therefore, we redesigned the SIU card using another FPGA based on flash technology. In order to detect bit errors in the user memory we added parity check logic to the design. The new SIU has been extensively tested using neutron and proton irradiation to verify its radiation tolerance. In this paper we summarize the design changes, introduce the final design, and the results of the radiation tolerance measurements on the final card.
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| 10. |
- Dénes, E., et al.
(författare)
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Radiation tolerant source interface unit for the ALICE experiment
- 2005
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Ingår i: Proceedings - 11th Workshop on Electronics for LHC and Future Experiments, LECC 2005. - : CERN. ; , s. 291-293
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Konferensbidrag (refereegranskat)abstract
- The ALICE Detector Data Link (DDL) is a high-speed optical link designed to interface the readout electronics of ALICE sub-detectors to the DAQ computers. The Source Interface Unit (SIU) of the DDL will operate in radiation environment. Tests showed that configuration loss of the Altera APEX II FPGA device used earlier on the DDL SIU card is only marginally acceptable. We developed a new version of the SIU card using Actel ProASIC+ device based on flash memory technology. The new SIU card has been extensively tested using neutron and proton irradiation. In this paper we present the SIU card and describe the results of irradiation measurements.
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