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Article
Open AccessPerformance of the ATLAS detector using first collision data
More than half a million minimum-bias events of LHC collision data were collected by the ATLAS experiment in December 2009 at centre-of-mass energies of 0.9 TeV and 2.36 TeV. This paper reports on studies of t...
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Article
Open AccessReadiness of the ATLAS Tile Calorimeter for LHC collisions
The Tile hadronic calorimeter of the ATLAS detector has undergone extensive testing in the experimental hall since its installation in late 2005. The readout, control and calibration systems have been fully op...
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Article
Open AccessThe ATLAS Simulation Infrastructure
The simulation software for the ATLAS Experiment at the Large Hadron Collider is being used for large-scale production of events on the LHC Computing Grid. This simulation requires many components, from the ge...
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Article
Open AccessThe ATLAS Inner Detector commissioning and calibration
The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took...
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Article
Open AccessCommissioning of the ATLAS Muon Spectrometer with cosmic rays
The ATLAS detector at the Large Hadron Collider has collected several hundred million cosmic ray events during 2008 and 2009. These data were used to commission the Muon Spectrometer and to study the performan...
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Article
Open AccessDrift Time Measurement in the ATLAS Liquid Argon Electromagnetic Calorimeter using Cosmic Muons
The ionization signals in the liquid argon of the ATLAS electromagnetic calorimeter are studied in detail using cosmic muons. In particular, the drift time of the ionization electrons is measured and used to a...
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Article
Open AccessReadiness of the ATLAS liquid argon calorimeter for LHC collisions
The ATLAS liquid argon calorimeter has been operating continuously since August 2006. At this time, only part of the calorimeter was readout, but since the beginning of 2008, all calorimeter cells have been co...
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Article
Open AccessMeasurement of the W → ℓν and Z/γ * → ℓℓ production cross sections in proton-proton collisions at \( \sqrt {s} = 7\;{\text{TeV}} \) with the ATLAS detector
First measurements of the W → ℓν and Z/γ * → ℓℓ (ℓ = e, μ) production cross sections in proton-proton collisions at
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Article
Open AccessMeasurement of inclusive jet and dijet cross sections in proton-proton collisions at 7 TeV centre-of-mass energy with the ATLAS detector
Jet cross sections have been measured for the first time in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector. The measurement uses an integrated luminosity of 17 nb−1 recorded...
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Article
Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \(\sqrt{s}=7\) TeV
A measurement of the production cross-section for top quark pairs ( \(t\bar{t}\) ) in pp collisions at ...
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Article
Open AccessStudies of the performance of the ATLAS detector using cosmic-ray muons
Muons from cosmic-ray interactions in the atmosphere provide a high-statistics source of particles that can be used to study the performance and calibration of the ATLAS detector. Cosmic-ray muons can penetrat...
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Article
Open AccessLuminosity determination in pp collisions at \(\sqrt{s} = 7\) TeV using the ATLAS detector at the LHC
Measurements of luminosity obtained using the ATLAS detector during early running of the Large Hadron Collider (LHC) at \(\sqrt{s} = 7\) ...
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Article
Open AccessMeasurements of underlying-event properties using neutral and charged particles in pp collisions at \(\sqrt{s}=900\) GeV and \(\sqrt{s}=7\) TeV with the ATLAS detector at the LHC
We present first measurements of charged and neutral particle-flow correlations in pp collisions using the ATLAS calorimeters. Data were collected in 2009 and 2010 at centre-of-mass energies of 900 GeV and 7 TeV....
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Article
Open AccessSearch for supersymmetric particles in events with lepton pairs and large missing transverse momentum in \(\sqrt{s}=7~\mbox{TeV}\) proton–proton collisions with the ATLAS experiment
Results are presented of searches for the production of supersymmetric particles decaying into final states with missing transverse momentum and exactly two isolated leptons in
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Article
Open AccessSearch for an excess of events with an identical flavour lepton pair and significant missing transverse momentum in \(\sqrt{s}=7\) TeV proton–proton collisions with the ATLAS detector
Results are presented of a search for particles decaying into final states with significant missing transverse momentum and exactly two identical flavour leptons (e, μ) of opposite charge in
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Open AccessMeasurement of dijet production with a veto on additional central jet activity in pp collisions at \( \sqrt {s} = 7 \) TeV using the ATLAS detector
A measurement of jet activity in the rapidity interval bounded by a dijet system is presented. Events are vetoed if a jet with transverse momentum greater than 20 GeV is found between the two boundary jets. Th...
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Article
Open AccessMeasurement of Wγ and Zγ production in proton-proton collisions at \( \sqrt {s} = 7 \) TeV with the ATLAS detector
We present studies of W and Z bosons with associated high energy photons produced in pp collisions at \( \sqrt {s} = 7 \) ...
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Article
Open AccessLimits on the production of the standard model Higgs boson in pp collisions at \(\sqrt{s} = 7\) TeV with the ATLAS detector
A search for the Standard Model Higgs boson at the Large Hadron Collider (LHC) running at a centre-of-mass energy of 7 TeV is reported, based on a total integrated luminosity of up to 40 pb−1 collected by the ATL...
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Article
Open AccessSearch for diphoton events with large missing transverse energy with 36 pb−1 of 7 TeV proton–proton collision data with the ATLAS detector
Making use of 36 pb−1 of proton–proton collision data at \(\sqrt{s} =7\) TeV, the ATLAS Collaboration has performed a search for ...
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Open AccessInclusive search for same-sign dilepton signatures in pp collisions at \( \sqrt {s} = 7 \) TeV with the ATLAS detector
An inclusive search is presented for new physics in events with two isolated leptons (e or μ) having the same electric charge. The data are selected from events collected from pp collisions at