| 1. |
- Aad, G., et al.
(författare)
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The ATLAS Experiment at the CERN Large Hadron Collider
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08003
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Forskningsöversikt (refereegranskat)abstract
- The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
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| 2. |
- Abata, E., et al.
(författare)
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Study of energy response and resolution of the ATLAS barrel calorimeter to hadrons of energies from 20 to 350 GeV
- 2010
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576 .- 0167-5087. ; 621:1-3, s. 134-150
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Tidskriftsartikel (refereegranskat)abstract
- A fully instrumented slice of the ATLAS detector was exposed to test beams from the SPS (Super Proton Synchrotron) at CERN in 2004. In this paper, the results of the measurements of the response of the barrel calorimeter to hadrons with energies in the range 20-350 GeV and beam impact points and angles corresponding to pseudo-rapidity values in the range 0.2-0.65 are reported. The results are compared to the predictions of a simulation program using the Geant 4 toolkit. (C) 2010 Published by Elsevier B.V.
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| 3. |
- Bergeås Kuutmann, Elin, et al.
(författare)
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Measurement of Pion and Proton Response and Longitudinal Shower Profiles up to 20 Nuclear Interaction Lengths with the ATLAS Tile Calorimeter
- 2010
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 615:2, s. 158-181
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Tidskriftsartikel (refereegranskat)abstract
- The response of pions and protons in the energy range of 20–180 GeV, produced at CERN's SPS H8 test-beam line in the ATLAS iron–scintillator Tile hadron calorimeter, has been measured. The test-beam configuration allowed the measurement of the longitudinal shower development for pions and protons up to 20 nuclear interaction lengths. It was found that pions penetrate deeper in the calorimeter than protons. However, protons induce showers that are wider laterally to the direction of the impinging particle. Including the measured total energy response, the pion-to-proton energy ratio and the resolution, all observations are consistent with a higher electromagnetic energy fraction in pion-induced showers. The data are compared with GEANT4 simulations using several hadronic physics lists. The measured longitudinal shower profiles are described by an analytical shower parametrization within an accuracy of 5–10%. The amount of energy leaking out behind the calorimeter is determined and parametrized as a function of the beam energy and the calorimeter depth. This allows for a leakage correction of test-beam results in the standard projective geometry.
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| 4. |
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| 5. |
- Berglund, Svante, et al.
(författare)
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The ATLAS Tile Calorimeter Digitizer
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; :3, s. P01004-
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Bohm, Christian, et al.
(författare)
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ATLAS TileCal Digitizer Test System and Quality Control
- 2004
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Ingår i: CERN Note: ATL-TILECAL-2004-009.
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Tidskriftsartikel (refereegranskat)abstract
- This document describes the tests of the quality control procedure for the ATLAS TileCal digitizer unit. Since the ATLAS detector will fill most of the space in the detector cavity it will be difficult to disassemble parts of the detector. Therefore quality control is extremely important for every part of ATLAS. In Stockholm the digitizer units are tested in a testbench to ensure functionality and reliability in the ATLAS environment. The document includes a brief description of the ATLAS TileCal digitizer system and a description of the testbench setup. It also includes a description of the tests preformed and of the quality control procedure developed in Stockholm together with a production status.
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| 7. |
- Bohm, Christian, et al.
(författare)
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ATLAS TileCal Timing
- 2004
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Ingår i: CERN Note: ATL-TILECAL-2004-008.
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Tidskriftsartikel (refereegranskat)abstract
- The ATLAS TileCal digitizer boards are designed to compensate for time delays in the calorimeter modules. In this report a method is described to determine the time delays and how to correct for them. The analysis is made using testbeam pion data from 2002 and 2003. The result shows that the sampling clock of the digitizers in the barrel calorimeter can be adjusted in such a way that there always is one sample within 1.5 ns from the pulse peak.
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| 8. |
- Lesser, Jonas, 1973-
(författare)
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Development and Test of the ATLAS Tile Calorimeter Digitizer
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The new LHC particle accelerator now being built at CERN will have a radically increased event rate and higher energy. To accommodate this, instrumentation for LHC experiments has had to be constructed using new ideas and the latest available technology. A part of this effort was the development and test of a digitizer unit for the hadron calorimeter (TileCal) of the ATLAS experiment. To try out ideas and promote system integration, prototypes were tested in a subsystem using a particle beam to simulate the final conditions. During the development of these prototypes an application-specific integrated circuit was constructed to control the digitizer system. Tests made at the test beam facility have verified that all requirements were met. The final digitizer design and its components were radiation tested to verify full functionallity in its radiation environment during the full ATLAS life-span. Test devices were also constructed to test all production units. In addition to the digitizer system, an optical readout link was designed to meet the requirements for the digitizer readout. Preliminary studies indicate that the digitizer could also be used in an upgraded LHC, with presently considered scenarios.
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| 9. |
- Åsman, Barbro, et al.
(författare)
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A Search for New Physics in Dijet Mass and Angular Distributions in 36 pb$^{-1}$ of $pp$ Collisions at $\sqrt{s}=7$ TeV Measured with the ATLAS Detector
- 2011
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 13, s. 053044-
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Tidskriftsartikel (refereegranskat)abstract
- A search for new interactions and resonances produced in LHC proton-proton (pp) collisions at a centre-of-mass energy root s = 7 TeV was performed with the ATLAS detector. Using a dataset with an integrated luminosity of 36 pb(-1), dijet mass and angular distributions were measured up to dijet masses of similar to 3.5 TeV and were found to be in good agreement with Standard Model predictions. This analysis sets limits at 95% CL on various models for new physics: an excited quark is excluded for mass between 0.60 and 2.64 TeV, an axigluon hypothesis is excluded for axigluon masses between 0.60 and 2.10 TeV and quantum black holes are excluded in models with six extra space-time dimensions for quantum gravity scales between 0.75 and 3.67 TeV. Production cross section limits as a function of dijet mass are set using a simplified Gaussian signal model to facilitate comparisons with other hypotheses. Analysis of the dijet angular distribution using a novel technique simultaneously employing the dijet mass excludes quark contact interactions with a compositeness scale 3 below 9.5 TeV.
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| 10. |
- Åsman, Barbro, et al.
(författare)
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Measurement of the $W\to\ell\nu$ and $Z/gamma^\ast\to\ell\ell$ Production Cross Sections in Proton-Proton Collisions at $\sqrt{s}=7$ TeV with the ATLAS Detector
- 2010
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :12, s. 060-
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Tidskriftsartikel (refereegranskat)abstract
- First measurements of the W → ℓν and Z/γ * → ℓℓ (ℓ = e, μ) production cross sections in proton-proton collisions at Ös = 7 \textTeV s=7TeV are presented using data recorded by the ATLAS experiment at the LHC. The results are based on 2250 W → ℓν and 179 Z/γ * → ℓℓ candidate events selected from a data set corresponding to an integrated luminosity of approximately 320 nb. The measured total W and Z/γ ∗-boson production cross sections times the respective leptonic branching ratios for the combined electron and muon channels are sW\texttot Wtot. BR(W → ℓν) = 9.96 ± 0.23(stat) ± 0.50(syst) ± 1.10(lumi) nb and sZ / g \texttot totZ BR(Z/γ ∗ → ℓℓ) = 0.82 ± 0.06 (stat) ± 0.05 (syst) ± 0.09(lumi) nb (within the invariant mass window 66 < m ℓℓ < 116GeV). The W/Z cross-section ratio is measured to be 11.7 ± 0.9(stat) ± 0.4(syst). In addition, measurements of the W + and W − production cross sections and of the lepton charge asymmetry are reported. Theoretical predictions based on NNLO QCD calculations are found to agree with the measurements
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