| 1. |
- Almehed, Sverker, et al.
(author)
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Regional research exploitation of the LHC: A case-study of the required computing resources
- 2002
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In: Computer Physics Communications. - 0010-4655. ; 145:3, s. 341-350
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Journal article (peer-reviewed)abstract
- A simulation study to evaluate the required computing resources for a research exploitation of the Large Hadron Collider (LHC) has been performed. The evaluation,vas done as a case study. assuming existence of a Nordic regional centre and using the requirements for per-forming a specific physics analysis as a yard-stick. Other input parameters were: assumption for the distribution of researchers at the institutions involved, an analysis model, and two different functional structures of the computing resources.
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| 2. |
- Capeans, M., et al.
(author)
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Recent aging studies for the ATLAS transition radiation tracker
- 2004
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In: IEEE Transactions on Nuclear Science. ; 51, s. 960-967
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Conference paper (peer-reviewed)abstract
- The transition radiation tracker (TRT) is one of the three subsystems of the inner detector of the ATLAS experiment. It is designed to operate for 10 yr at the LHC, with integrated charges of /spl sim/10 C/cm of wire and radiation doses of about 10 Mrad and 2/spl times/10/sup 14/ neutrons/cm/sup 2/. These doses translate into unprecedented ionization currents and integrated charges for a large-scale gaseous detector. This paper describes studies leading to the adoption of a new ionization gas regime for the ATLAS TRT. In this new regime, the primary gas mixture is 70%Xe-27%CO/sub 2/-3%O/sub 2/. It is planned to occasionally flush and operate the TRT detector with an Ar-based ternary mixture, containing a small percentage of CF/sub 4/, to remove, if needed, silicon pollution from the anode wires. This procedure has been validated in realistic conditions and would require a few days of dedicated operation. This paper covers both performance and aging studies with the new TRT gas mixture.
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| 3. |
- Driouichi, Chafik
(author)
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B-physics potential of the ATLAS experiment and performance of the ATLAS Transition Radiation Tracker
- 2004
-
Doctoral thesis (other academic/artistic)abstract
- The ATLAS experiment is one of the four experiments at the Large Hadron Collider (LHC), which is supposed to be operational in early 2007. Proton-proton collisions at an unprecedented center-of-mass energy of 14 TeV will probe new frontiers of the universe, hopefully providing a better understanding of the laws governing our universe. Although the ATLAS detector has been optimized to search for the Higgs boson within the full expected mass range and other new particles, it is well adapted to cover a wide range of B-physics topics. The determination of the angles of the Unitarity Triangle, and measurements of CP violation are also a key point for a full and coherent understanding of the fundamental forces governing the universe. Intriguing particles, such as the $ m{B_{c}}$ meson, provide a very interesting case to study the interplay of strong and weak interactions, a key problem in the theoretical analysis of the weak decays of hadrons. The Transition Radiation Tracker (TRT) is a combined straw drift tube and transition radiation detector. It provides a combination of continuous tracking with many projective measurements based on individual drift tubes and of a powerful electron identification based on radiator fibers or foils interleaved with the straws. An extensive program of tests undertaken on several small scale prototypes has shown a good and satisfactory performance.
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| 4. |
- Driouichi, Chafik, et al.
(author)
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Observation potential of the decays B0s,d → J/ψη
- 2002
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In: EPJ direct. - 1435-3725. ; 4:CN2, s. 1-13
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Journal article (peer-reviewed)abstract
- The observation potential of the decays B0s,d → J/ψη with the ATLAS detector at the LHC is described in this paper. At present there exist only upper limits for the branching fractions, but at LHC, a clear signal for the decay mode B0s,d → J/ψη is expected. The branching fraction of this decay mode can thus be measured, and other parameters such as B0s lifetime can be measured as well. The decay mode B0s → J/ψη is analogous to the mode B0s → J/ψφ, which has been studied extensively in view of CP violation measurements. In these two decay modes, the CP asymmetry predicted by the Standard Model is very small, and the observation of a sizeable effect would be a signal of physics beyond the Standard Model. The decay mode J/ψη constitutes thus a cross-check for the mode J/ψφ. Furthermore, the former final state is a CP-eigenstate and no angular analysis is thus needed. The reconstruction of η-mesons at LHC experiments has not been addressed before, and therefore the study presented here can also be regarded as an example of the physics prospects with η-mesons at the LHC.
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| 5. |
- Åkesson, Torsten, et al.
(author)
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ATLAS Transition Radiation Tracker test-beam results
- 2004
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In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 522:1-2, s. 50-55
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Conference paper (peer-reviewed)abstract
- Several prototypes of the Transition Radiation Tracker for the ATLAS experiment at the LHC have been built and tested at the CERN SPS accelerator. Results from detailed studies of the straw-tube hit registration efficiency and drift-time measurements and of the pion and electron spectra without and with radiators are presented.
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| 6. |
- Åkesson, Torsten, et al.
(author)
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Operation of the ATLAS Transition Radiation Tracker under very high irradiation at the CERN LHC
- 2004
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In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 522:1-2, s. 25-32
-
Conference paper (peer-reviewed)abstract
- The ATLAS Transition Radiation Tracker (TRT) performance depends critically on the choice of the active gas and on its properties. The most important operational aspects, which have led to the final choice of the active gas for the operation of the TRT at the LHC design luminosity, are presented. The TRT performance expected at these conditions is reviewed, including pile-up effects at high luminosity. (C) 2004 Elsevier B.V. All rights reserved.
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| 7. |
- Åkesson, Torsten, et al.
(author)
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Status of design and construction of the Transition Radiation Tracker (TRT) for the ATLAS experiment at the LHC
- 2004
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In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 522:1-2, s. 131-145
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Journal article (peer-reviewed)abstract
- The ATLAS Inner Detector consists of three sub-systems, the Pixel Detector at the innermost radius, the Semi-Conductor Tracker at intermediate radii, and the Transition Radiation Tracker (TRT) at the outermost radius in front of the electromagnetic calorimeter. The TRT provides a combination of continuous tracking with many projective measurements based on individual drift-tubes (or straws) and of electron identification based on radiator fibres or foils interleaved between the straws themselves. This paper describes the current status of design and construction of the various components of the TRT: the assembly of the barrel modules has recently been completed, that of the end-cap wheels is well underway, and the on-detector front-end electronics is in production. The detector modules and front-end electronics boards will be integrated together over the next year, the barrel and end-cap TRT parts will be assembled and tested with their SCT counterparts during 2005 and installation and commissioning in the ATLAS pit will take place at the end of 2005 and the beginning of 2006. (C) 2004 Elsevier B.V. All rights reserved.
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