-
G. ATLAS Collaboration Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz,
H. Abreu, [......],
R. Zitoun,
L. Živković,
V. V. Zmouchko,
G. Zobernig,
A. Zoccoli,
Y. Zolnierowski,
A. Zsenei,
M. zur Nedden,
V. Zutshi,
L. Zwalinski
[show abstract]
[hide abstract]
ABSTRACT: A measurement of the production cross-section for top quark pairs
(tt¯) in pp collisions at s=7 TeV is presented using data
recorded with the ATLAS detector at the Large Hadron Collider. Events
are selected in the single lepton topology by requiring an electron or
muon, large missing transverse momentum and at least three jets. With a
data sample of 35 pb-1, two different multivariate
methods, one of which uses b-quark jet identification while the other
does not, use kinematic variables to obtain cross-section measurements
of
σ=187±11(stat.)-17+18(syst.)±6(lumi.) pb
and
σ=173±17(stat.)-16+18(syst.)±6(lumi.) pb
respectively. The two measurements are in agreement with each other and
with QCD calculations. The first measurement has a better a priori
sensitivity and constitutes the main result of this Letter.
Physics Letters B 04/2012; 711:244-263. · 3.95 Impact Factor
-
The ATLAS Collaboration,
G. Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz, [......],
X. Zhuang,
V. Zhuravlov,
R. Zimmermann,
S. Zimmermann,
M. Ziolkowski,
L. Živković,
G. Zobernig,
A. Zoccoli,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
ABSTRACT: 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 penetrate to the cavern and deposit energy in
all detector subsystems. Such events have played an important role in the commissioning of the detector since the start of
the installation phase in 2005 and were particularly important for understanding the detector performance in the time prior
to the arrival of the first LHC beams. Global cosmic-ray runs were undertaken in both 2008 and 2009 and these data have been
used through to the early phases of collision data-taking as a tool for calibration, alignment and detector monitoring. These
large datasets have also been used for detector performance studies, including investigations that rely on the combined performance
of different subsystems. This paper presents the results of performance studies related to combined tracking, lepton identification
and the reconstruction of jets and missing transverse energy. Results are compared to expectations based on a cosmic-ray event
generator and a full simulation of the detector response.
European Physical Journal C 04/2012; 71(3):1-36. · 3.63 Impact Factor
-
The ATLAS Collaboration,
G. Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz, [......],
M. Ziolkowski,
R. Zitoun,
L. Živković,
V. V. Zmouchko,
G. Zobernig,
A. Zoccoli,
Y. Zolnierowski,
A. Zsenei,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
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 \sqrt {s} = 7\;{\text{TeV}} 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 \sigma_W^{\text{tot}} . BR(W → ℓν) = 9.96 ± 0.23(stat) ± 0.50(syst) ± 1.10(lumi) nb and
sZ /
g \texttot \sigma_{{{Z} \left/ {\gamma } \right.}}^{\text{tot}} 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.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2010(12):1-65. · 5.83 Impact Factor
-
The ATLAS Collaboration,
G. Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz, [......],
M. Ziolkowski,
R. Zitoun,
L. Živković,
V. V. Zmouchko,
G. Zobernig,
A. Zoccoli,
Y. Zolnierowski,
A. Zsenei,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
ABSTRACT: Jet cross sections have been measured for the first time in proton-proton collisions at a centre-of-mass energy of 7TeV using
the ATLAS detector. The measurement uses an integrated luminosity of 17nb−1 recorded at the Large Hadron Collider. The anti-k
t
algorithm is used to identify jets, with two jet resolution parameters, R=0.4 and 0.6. The dominant uncertainty comes from the jet energy scale, which is determined to within 7% for central jets
above 60GeV transverse momentum. Inclusive single-jet differential cross sections are presented as functions of jet transverse
momentum and rapidity. Dijet cross sections are presented as functions of dijet mass and the angular variableχ. The results are compared to expectations based on next-to-leading-order QCD, which agree with the data, providing a validation
of the theory in a new kinematic regime.
European Physical Journal C 04/2012; 71(2):1-59. · 3.63 Impact Factor
-
The ATLAS Collaboration,
G. Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz, [......],
X. Zhuang,
V. Zhuravlov,
R. Zimmermann,
S. Zimmermann,
M. Ziolkowski,
L. Živković,
G. Zobernig,
A. Zoccoli,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
ABSTRACT: The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a
2T magnetic field. Its installation was completed in August 2008 and the detector took part in data-taking with single LHC
beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking
performance has been measured with 7.6million cosmic-ray events, collected using a tracking trigger and reconstructed with
modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close
to 100%. Lorentz angle measurements for both electrons and holes, specific energy-loss calibration and transition radiation
turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry.
After the initial alignment, a transverse impact parameter resolution of 22.1±0.9μm and a relative momentum resolution σ
p
/p=(4.83±0.16)×10−4 GeV−1×p
T have been measured for high momentum tracks.
European Physical Journal C 04/2012; 70(3):787-821. · 3.63 Impact Factor
-
The ATLAS Collaboration,
G. Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz, [......],
X. Zhuang,
V. Zhuravlov,
R. Zimmermann,
S. Zimmermann,
M. Ziolkowski,
L. Živković,
G. Zobernig,
A. Zoccoli,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
ABSTRACT: 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 performance of the trigger and tracking chambers,
their alignment, the detector control system, the data acquisition and the analysis programs. We present the performance in
the relevant parameters that determine the quality of the muon measurement. We discuss the single element efficiency, resolution
and noise rates, the calibration method of the detector response and of the alignment system, the track reconstruction efficiency
and the momentum measurement. The results show that the detector is close to the design performance and that the Muon Spectrometer
is ready to detect muons produced in high energy proton–proton collisions.
European Physical Journal C 04/2012; 70(3):875-916. · 3.63 Impact Factor
-
The ATLAS Collaboration,
G. Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz, [......],
X. Zhuang,
V. Zhuravlov,
R. Zimmermann,
S. Zimmermann,
M. Ziolkowski,
L. Živković,
G. Zobernig,
A. Zoccoli,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
ABSTRACT: 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 operational since 2007 and the detector has successfully
collected data from the LHC single beams in 2008 and first collisions in 2009. This paper gives an overview of the Tile Calorimeter
performance as measured using random triggers, calibration data, data from cosmic ray muons and single beam data. The detector
operation status, noise characteristics and performance of the calibration systems are presented, as well as the validation
of the timing and energy calibration carried out with minimum ionising cosmic ray muons data. The calibration systems’ precision
is well below the design value of 1%. The determination of the global energy scale was performed with an uncertainty of 4%.
European Physical Journal C 04/2012; 70(4):1193-1236. · 3.63 Impact Factor
-
The ATLAS collaboration,
G. Aad,
E. Abat,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins, [......],
M. Ziolkowski,
R. Zitoun,
L. Živković,
V. V. Zmouchko,
G. Zobernig,
A. Zoccoli,
Y. Zolnierowski,
A. Zsenei,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
ABSTRACT: 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 the initial performance of the ATLAS
detector from these data. Comparisons between data and Monte Carlo predictions are shown for distributions of several track-and
calorimeter-based quantities. The good performance of the ATLAS detector in these first data gives confidence for successful
running at higher energies.
KeywordsHadron-Hadron Scattering
Journal of High Energy Physics 04/2012; 2010(9):1-66. · 5.83 Impact Factor
-
The ATLAS Collaboration,
G. Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz, [......],
X. Zhuang,
V. Zhuravlov,
R. Zimmermann,
S. Zimmermann,
M. Ziolkowski,
L. Živković,
G. Zobernig,
A. Zoccoli,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
ABSTRACT: 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 generators that simulate particle collisions,
through packages simulating the response of the various detectors and triggers. All of these components come together under
the ATLAS simulation infrastructure. In this paper, that infrastructure is discussed, including that supporting the detector
description, interfacing the event generation, and combining the GEANT4 simulation of the response of the individual detectors.
Also described are the tools allowing the software validation, performance testing, and the validation of the simulated output
against known physics processes.
European Physical Journal C 04/2012; 70(3):823-874. · 3.63 Impact Factor
-
The ATLAS Collaboration,
G. Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz, [......],
R. Zimmermann,
S. Zimmermann,
M. Ziolkowski,
R. Zitoun,
L. Živković,
V. V. Zmouchko,
G. Zobernig,
A. Zoccoli,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
ABSTRACT: 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 connected to the ATLAS readout system in preparation
for LHC collisions. This paper gives an overview of the liquid argon calorimeter performance measured in situ with random
triggers, calibration data, cosmic muons, and LHC beam splash events. Results on the detector operation, timing performance,
electronics noise, and gain stability are presented. High energy deposits from radiative cosmic muons and beam splash events
allow to check the intrinsic constant term of the energy resolution. The uniformity of the electromagnetic barrel calorimeter
response along η (averaged overφ) is measured at the percent level using minimum ionizing cosmic muons. Finally, studies of electromagnetic showers from radiative
muons have been used to cross-check the Monte Carlo simulation. The performance results obtained using the ATLAS readout,
data acquisition, and reconstruction software indicate that the liquid argon calorimeter is well-prepared for collisions at
the dawn of the LHC era.
European Physical Journal C 04/2012; 70(3):723-753. · 3.63 Impact Factor
-
The ATLAS Collaboration,
G. Aad,
B. Abbott,
J. Abdallah,
A. A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M. Abolins,
H. Abramowicz, [......],
R. Zimmermann,
S. Zimmermann,
M. Ziolkowski,
R. Zitoun,
L. Živković,
V. V. Zmouchko,
G. Zobernig,
A. Zoccoli,
M. zur Nedden,
V. Zutshi
[show abstract]
[hide abstract]
ABSTRACT: 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 assess the intrinsic uniformity of the calorimeter
gaps and estimate its impact on the constant term of the energy resolution. The drift times of electrons in the cells of the
second layer of the calorimeter are uniform at the level of 1.3% in the barrel and 2.8% in the endcaps. This leads to an estimated
contribution to the constant term of (0.29+0.05-0.04)(0.29^{+0.05}_{-0.04})% in the barrel and (0.54+0.06-0.04)(0.54^{+0.06}_{-0.04})% in the endcaps. The same data are used to measure the drift velocity of ionization electrons in liquid argon, which is found
to be 4.61±0.07mm/μs at 88.5K and 1kV/mm.
European Physical Journal C 04/2012; 70(3):755-785. · 3.63 Impact Factor
-
G Aad,
B Abbott,
J Abdallah,
A A Abdelalim,
A Abdesselam,
O Abdinov,
B Abi,
M Abolins,
H Abramowicz,
H Abreu, [......],
R Zitoun,
L Zivković,
V V Zmouchko,
G Zobernig,
A Zoccoli,
Y Zolnierowski,
A Zsenei,
M zur Nedden,
V Zutshi,
L Zwalinski
[show abstract]
[hide abstract]
ABSTRACT: A search for the Higgs boson has been performed in the H→WW(*)→ℓ(+)νℓ(-)ν[over ¯] channel (ℓ=e/μ) with an integrated luminosity of 2.05 fb(-1) of pp collisions at √s=7 TeV collected with the ATLAS detector at the Large Hadron Collider. No significant excess of events over the expected background is observed and limits on the Higgs boson production cross section are derived for a Higgs boson mass in the range 110 GeV<m(H)<300 GeV. The observations exclude the presence of a standard model Higgs boson with a mass 145<m(H)<206 GeV at 95% confidence level.
Physical Review Letters 03/2012; 108(11):111802. · 7.37 Impact Factor
-
G Aad,
B Abbott,
J Abdallah,
A A Abdelalim,
A Abdesselam,
O Abdinov,
B Abi,
M Abolins,
H Abramowicz,
H Abreu, [......],
M Ziolkowski,
R Zitoun,
L Zivković,
V V Zmouchko,
G Zobernig,
A Zoccoli,
Y Zolnierowski,
A Zsenei,
M Zur Nedden,
V Zutshi
[show abstract]
[hide abstract]
ABSTRACT: A search for new heavy particles manifested as resonances in two-jet final states is presented. The data were produced in 7 TeV proton-proton collisions by the LHC and correspond to an integrated luminosity of 315 nb⁻¹ collected by the ATLAS detector. No resonances were observed. Upper limits were set on the product of cross section and signal acceptance for excited-quark (q*) production as a function of q* mass. These exclude at the 95% C.L. the q* mass interval 0.30<m(q*)<1.26 TeV, extending the reach of previous experiments.
Physical Review Letters 10/2010; 105(16):161801. · 7.37 Impact Factor
-
E Abat,
A Abdesselam,
T N Addy,
T P A Åkesson,
P P Allport,
L Andricek,
F Anghinolfi,
R Apsimon,
E Arik,
M Arik, [......],
D Whittington,
A Wildauer,
I Wilhelm,
H H Williams,
J A Wilson,
M W Wolter,
S L Wu,
A Zhelezko,
H Z Zhu,
A Zsenei
[show abstract]
[hide abstract]
ABSTRACT: The ATLAS (A Toroidal LHC ApparatuS) Inner Detector provides charged particle tracking in the centre of the ATLAS experiment at the Large Hadron Collider (LHC). The Inner Detector consists of three subdetectors: the Pixel Detector, the Semiconductor Tracker (SCT), and the Transition Radiation Tracker (TRT). This paper summarizes the tests that were carried out at the final stage of SCT+TRT integration prior to their installation in ATLAS. The combined operation and performance of the SCT and TRT barrel and endcap detectors was investigated through a series of noise tests, and by recording the tracks of cosmic rays. This was a crucial test of hardware and software of the combined tracker detector systems. The results of noise and cross-talk tests on the SCT and TRT in their final assembled configuration, using final readout and supply hardware and software, are reported. The reconstruction and analysis of the recorded cosmic tracks allowed testing of the offline analysis chain and verification of basic tracker performance parameters, such as efficiency and spatial resolution, in combined operation before installation.
Journal of Instrumentation 08/2008; 3(08):P08003. · 1.87 Impact Factor
-
G Grzelak,
A Reichold,
J Dale,
M Dawson,
J Green,
Y. Han,
M Jones,
G. Moss,
B. Ottewell, R Wastie,
D. Kämptner,
J. Prenting,
M. Schlösser
[show abstract]
[hide abstract]
ABSTRACT: Linear Collider Alignment and Survey (LiCAS) R&D group is proposing a novel automated metrology instrument dedicated to align and monitor the mechanical stability of a future linear high energy e+e- collider. LiCAS uses Laser Straightness Monitors (LSM) and Frequency Scanning Interferometry (FSI) for straightness and absolute distance measurements, respectively. This paper presents detailed simulations of a LiCAS system operating inside a Rapid Tunnel Reference Surveyor (RTRS train). With the proposed design it is feasible to achieve the required vertical accuracy of the order of 200 micons over 600 m tunnel sections meeting the specification for the TESLA collider.
10/2007;
-
E Abate,
A. Abdesselam,
TN Addy,
TPA Akesson,
PP Allport,
L. Andricek,
F. Anghinolfi,
R Apsimon,
E Arik,
M. Arik, [......],
D. Whittington,
A. Wildauer,
I Wilhelm,
HH Williams,
JA Wilson,
MW Wolter,
SL Wu,
A. Zhelezko,
HZ Zhu,
A Zsenei
-
G. Aad,
E. Abat,
B Abbott,
J Abdallah,
A.A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M Abolins,
H Abramowicz, [......],
M Ziolkowski,
R Zitoun,
L Zivkovic,
V.V. Zmouchko,
G Zobernig,
A. Zoccoli,
Y Zolnierowski,
A Zsenei,
M zur Nedden,
V Zutshi
[show abstract]
[hide abstract]
ABSTRACT: The first measurements from proton-proton collisions recorded with the ATLAS detector at the LHC are presented. Data were collected in December 2009 using a minimum-bias trigger during collisions at a centre-of-mass energy of 900 GeV. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity, and the relationship between mean transverse momentum and charged-particle multiplicity are measured for events with at least one charged particle in the kinematic range |eta|<2.5 and pT>500 MeV. The measurements are compared to Monte Carlo models of proton-proton collisions and to results from other experiments at the same centre-of-mass energy. The charged-particle multiplicity per event and unit of pseudorapidity at eta = 0 is measured to be 1.333 +/- 0.003 (stat.) +/- 0.040 (syst.), which is 5-15% higher than the Monte Carlo models predict.
Physics Letters B.
-
G. Aad,
B Abbott,
J Abdallah,
A.A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M Abolins,
H Abramowicz,
H. Abreu, [......],
X. Zhuang,
V Zhuravlov,
R Zimmermann,
S Zimmermann,
M Ziolkowski,
L Zivkovic,
G Zobernig,
A. Zoccoli,
M zur Nedden,
V Zutshi
[show abstract]
[hide abstract]
ABSTRACT: 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 performance of the trigger and tracking chambers, their alignment, the detector control system, the data acquisition and the analysis programs. We present the performance in the relevant parameters that determine the quality of the muon measurement. We discuss the single element efficiency, resolution and noise rates, the calibration method of the detector response and of the alignment system, the track reconstruction efficiency and the momentum measurement. The results show that the detector is close to the design performance and that the Muon Spectrometer is ready to detect muons produced in high energy proton-proton collisions.
-
G. Aad,
B Abbott,
J Abdallah,
A.A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M Abolins,
H Abramowicz,
H. Abreu, [......],
M Ziolkowski,
R Zitoun,
L. Živkovic,
V.V. Zmouchko,
G Zobernig,
A. Zoccoli,
Y Zolnierowski,
A Zsenei,
M zur Nedden,
V Zutshi
[show abstract]
[hide abstract]
ABSTRACT: Dijet angular distributions from the first LHC pp collisions at center-of-mass energy sqrt(s) = 7 TeV have been measured with the ATLAS detector. The dataset used for this analysis represents an integrated luminosity of 3.1 pb-1. Dijet $\chi$ distributions and centrality ratios have been measured up to dijet masses of 2.8 TeV, and found to be in good agreement with Standard Model predictions. Analysis of the $\chi$ distributions excludes quark contact interactions with a compositeness scale $\Lambda$ below 3.4 TeV, at 95% confidence level, significantly exceeding previous limits.
Physics Letters B.
-
G. Aad,
B Abbott,
J Abdallah,
A.A. Abdelalim,
A. Abdesselam,
O. Abdinov,
B. Abi,
M Abolins,
H Abramowicz,
H. Abreu, [......],
R Zimmermann,
S Zimmermann,
M Ziolkowski,
R Zitoun,
L Zivkovic,
V.V. Zmouchko,
G Zobernig,
A. Zoccoli,
M zur Nedden,
V Zutshi
[show abstract]
[hide abstract]
ABSTRACT: 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 connected to the ATLAS readout system in preparation for LHC collisions. This paper gives an overview of the liquid argon calorimeter performance measured in situ with random triggers, calibration data, cosmic muons, and LHC beam splash events. Results on the detector operation, timing performance, electronics noise, and gain stability are presented. High energy deposits from radiative cosmic muons and beam splash events allow to check the intrinsic constant term of the energy resolution. The uniformity of the electromagnetic barrel calorimeter response along eta (averaged over phi) is measured at the percent level using minimum ionizing cosmic muons. Finally, studies of electromagnetic showers from radiative muons have been used to cross-check the Monte Carlo simulation. The performance results obtained using the ATLAS readout, data acquisition, and reconstruction software indicate that the liquid argon calorimeter is well-prepared for collisions at the dawn of the LHC era.
European Physical Journal C.
