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• 1. Chatrchyan, S
Alignment of the CMS Muon System with Cosmic-Ray and Beam-Halo Muons2010In: JINST, Vol. 5Article in journal (Refereed)
• 2. Chatrchyan, S
Alignment of the CMS Silicon Tracker during Commissioning with Cosmic Rays2010In: JINST, Vol. 5Article in journal (Refereed)
• 3. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Aligning the CMS Muon Chambers with the Muon Alignment System during an Extended Cosmic Ray Run2010In: journal of instumentation, Vol. 5Article in journal (Refereed)

The alignment system for the muon spectrometer of the CMS detector comprises three independent subsystems of optical and analog position sensors. It aligns muon chambers with respect to each other and to the central silicon tracker. System commissioning at full magnetic field began in 2008 during an extended cosmic ray run. The system succeeded in tracking muon detector movements of up to 18 mm and rotations of several milliradians under magnetic forces. Depending on coordinate and subsystem, the system achieved chamber alignment precisions of 140–350 μm and 30–200 μrad, close to the precision requirements of the experiment. Systematic errors on absolute positions are estimated to be 340–590 μm based on comparisons with independent photogrammetry measurements.

• 4. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Calibration of the CMS Drift Tube Chambers and Measurement of the Drift Velocity with Cosmic Rays2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

This paper describes the calibration procedure for the drift tubes of the CMS barrel muon system and reports the main results obtained with data collected during a high statistics cosmic ray data-taking period. The main goal of the calibration is to determine, for each drift cell, the minimum time delay for signals relative to the trigger, accounting for the drift velocity within the cell. The accuracy of the calibration procedure is influenced by the random arrival time of the cosmic muons relative to the LHC clock cycle. A more refined analysis of the drift velocity was performed during the offline reconstruction phase, which takes into account this feature of cosmic ray events

• 5. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
CMS Data Processing Workflows during an Extended Cosmic Ray Run2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

The CMS Collaboration conducted a month-long data taking exercise, the Cosmic Run At Four Tesla, during October-November 2008, with the goal of commissioning the experiment for extended operation. With all installed detector systems participating, CMS recorded 270 million cosmic ray events with the solenoid at a magnetic field strength of 3.8 T. This paper describes the data flow from the detector through the various online and offline computing systems, as well as the workflows used for recording the data, for aligning and calibrating the detector, and for analysis of the data.

• 6. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Commissioning of the CMS Experiment and the Cosmic Run at Four Tesla2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

The CMS Collaboration conducted a month-long data-taking exercise known as the Cosmic Run At Four Tesla in late 2008 in order to complete the commissioning of the experiment for extended operation. The operational lessons resulting from this exercise were addressed in the subsequent shutdown to better prepare CMS for LHC beams in 2009. The cosmic data collected have been invaluable to study the performance of the detectors, to commission the alignment and calibration techniques, and to make several cosmic ray measurements. The experimental setup, conditions, and principal achievements from this data-taking exercise are described along with a review of the preceding integration activities.

• 7. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Commissioning of the CMS High-Level Trigger with Cosmic Rays2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

The CMS High-Level Trigger (HLT) is responsible for ensuring that data samples with potentially interesting events are recorded with high efficiency and good quality. This paper gives an overview of the HLT and focuses on its commissioning using cosmic rays. The selection of triggers that were deployed is presented and the online grouping of triggered events into streams and primary datasets is discussed. Tools for online and offline data quality monitoring for the HLT are described, and the operational performance of the muon HLT algorithms is reviewed. The average time taken for the HLT selection and its dependence on detector and operating conditions are presented. The HLT performed reliably and helped provide a large dataset. This dataset has proven to be invaluable for understanding the performance of the trigger and the CMS experiment as a whole.

• 8. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Identification and Filtering of Uncharacteristic Noise in the CMS Hadron Calorimeter2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

Commissioning studies of the CMS hadron calorimeter have identified sporadic uncharacteristic noise and a small number of malfunctioning calorimeter channels. Algorithms have been developed to identify and address these problems in the data. The methods have been tested on cosmic ray muon data, calorimeter noise data, and single beam data collected with CMS in 2008. The noise rejection algorithms can be applied to LHC collision data at the trigger level or in the offline analysis. The application of the algorithms at the trigger level is shown to remove 90% of noise events with fake missing transverse energy above 100 GeV, which is sufficient for the CMS physics trigger operation.

• 9. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Performance and Operation of the CMS Electromagnetic Calorimeter2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75 848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented. Export citation and abstract

• 10. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Performance of CMS Hadron Calorimeter Timing and Synchronization using Test Beam, Cosmic Ray, and LHC Beam Data2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

This paper discusses the design and performance of the time measurement technique and of the synchronization systems of the CMS hadron calorimeter. Time measurement performance results are presented from test beam data taken in the years 2004 and 2006. For hadronic showers of energy greater than 100 GeV, the timing resolution is measured to be about 1.2 ns. Time synchronization and out-of-time background rejection results are presented from the Cosmic Run At Four Tesla and LHC beam runs taken in the Autumn of 2008. The inter-channel synchronization is measured to be within ±2 ns.

• 11. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Performance of the CMS Drift Tube Chambers with Cosmic Rays2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

Studies of the performance of the CMS drift tube barrel muon system are described, with results based on data collected during the CMS Cosmic Run at Four Tesla. For most of these data, the solenoidal magnet was operated with a central field of 3.8 T. The analysis of data from 246 out of a total of 250 chambers indicates a very good muon reconstruction capability, with a coordinate resolution for a single hit of about 260 μm, and a nearly 100% efficiency for the drift tube cells. The resolution of the track direction measured in the bending plane is about 1.8 mrad, and the efficiency to reconstruct a segment in a single chamber is higher than 99%. The CMS simulation of cosmic rays reproduces well the performance of the barrel muon detector.

• 12. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Performance Study of the CMS Barrel Resistive Plate Chambers with Cosmic Rays2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

In October and November 2008, the CMS collaboration conducted a programme of cosmic ray data taking, which has recorded about 270 million events. The Resistive Plate Chamber system, which is part of the CMS muon detection system, was successfully operated in the full barrel. More than 98% of the channels were operational during the exercise with typical detection efficiency of 90%. In this paper, the performance of the detector during these dedicated runs is reported.

• 13. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Precise Mapping of the Magnetic Field in the CMS Barrel Yoke using Cosmic Rays2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

The CMS detector is designed around a large 4 T superconducting solenoid, enclosed in a 12 000-tonne steel return yoke. A detailed map of the magnetic field is required for the accurate simulation and reconstruction of physics events in the CMS detector, not only in the inner tracking region inside the solenoid but also in the large and complex structure of the steel yoke, which is instrumented with muon chambers. Using a large sample of cosmic muon events collected by CMS in 2008, the field in the steel of the barrel yoke has been determined with a precision of 3 to 8% depending on the location

• 14. Chatrchyan, S
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Time Reconstruction and Performance of the CMS Electromagnetic Calorimeter2010In: Journal of Instrumentation, Vol. 5Article in journal (Refereed)

The resolution and the linearity of time measurements made with the CMS electromagnetic calorimeter are studied with samples of data from test beam electrons, cosmic rays, and beam-produced muons. The resulting time resolution measured by lead tungstate crystals is better than 100 ps for energy deposits larger than 10 GeV. Crystal-to-crystal synchronization with a precision of 500 ps is performed using muons produced with the first LHC beams in 2008

• 15. Chatrchyan, S.
Univ Cantabria, CSIC, Inst Fis Cantabria IFCA, E-39005 Santander, Spain.
Performance of the CMS drift-tube chamber local trigger with cosmic rays2010In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 5, article id T03003Article in journal (Refereed)

The performance of the Local Trigger based on the drift-tube system of the CMS experiment has been studied using muons from cosmic ray events collected during the commissioning of the detector in 2008. The properties of the system are extensively tested and compared with the simulation. The effect of the random arrival time of the cosmic rays on the trigger performance is reported, and the results are compared with the design expectations for proton-proton collisions and with previous measurements obtained with muon beams.

• 16. Chatrchyan, S.
Univ Cantabria, CSIC, IFCA, E-39005 Santander, Spain.
Performance of the CMS hadron calorimeter with cosmic ray muons and LHC beam data2010In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 5, article id T03012Article in journal (Refereed)

The CMS Hadron Calorimeter in the barrel, endcap and forward regions is fully commissioned. Cosmic ray data were taken with and without magnetic field at the surface hall and after installation in the experimental hall, hundred meters underground. Various measurements were also performed during the few days of beam in the LHC in September 2008. Calibration parameters were extracted, and the energy response of the HCAL determined from test beam data has been checked.

• 17.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Charged particle multiplicities in $pp$ interactions at $\sqrts=0.9$, 2.36, and 7 TeV2011In: JHEP, Vol. 01Article in journal (Refereed)
• 18.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
CMS Tracking Performance Results from early LHC Operation2010In: Eur. Phys. J., Vol. C70, p. 1165-1192Article in journal (Refereed)
• 19.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Commissioning and Performance of the CMS Pixel Tracker with Cosmic Ray Muons2010In: JINST, Vol. 5Article in journal (Refereed)
• 20.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Commissioning and Performance of the CMS Silicon Strip Tracker with Cosmic Ray Muons2010In: JINST, Vol. 5Article in journal (Refereed)
• 21.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Dijet Azimuthal Decorrelations in $pp$ Collisions at $\sqrts = 7$ TeV2011In: Phys. Rev. Lett., Vol. 106Article in journal (Refereed)
• 22.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
First Measurement of Bose-Einstein Correlations in proton-proton Collisions at $\sqrts$ =0.9 and 2.36 TeV at the LHC2010In: Phys. Rev. Lett., Vol. 105Article in journal (Refereed)
• 23.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
First Measurement of Hadronic Event Shapes in $pp$ Collisions at $\sqrt s=7$ TeV2011In: Phys. Lett., Vol. B699, p. 48-67Article in journal (Refereed)
• 24.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
First Measurement of the Cross Section for Top-Quark Pair Production in Proton-Proton Collisions at $\sqrts=7$ TeV2011In: Phys. Lett., Vol. B695, p. 424-443Article in journal (Refereed)
• 25.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
First Measurement of the Underlying Event Activity at the LHC with $\sqrts = 0.9$ TeV2010In: Eur. Phys. J., Vol. C70, p. 555-572Article in journal (Refereed)
• 26.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Inclusive b-hadron production cross section with muons in $pp$ collisions at $\sqrts = 7$ TeV2011In: JHEP, Vol. 03Article in journal (Refereed)
• 27.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Measurement of $B\barB$ Angular Correlations based on Secondary Vertex Reconstruction at $\sqrts=7$ TeV2011In: JHEP, Vol. 03Article in journal (Refereed)
• 28.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Measurement of Bose-Einstein Correlations in $pp$ Collisions at $\sqrts=0.9$ and 7 TeV2011In: JHEP, Vol. 05Article in journal (Refereed)
• 29.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Measurement of Dijet Angular Distributions and Search for Quark Compositeness in pp Collisions at $sqrts = 7$ TeV2011In: Phys. Rev. Lett., Vol. 106Article in journal (Refereed)
• 30.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Measurement of the $B^+$ Production Cross Section in pp Collisions at $\sqrts = 7$ TeV2011In: Phys. Rev. Lett., Vol. 106Article in journal (Refereed)
• 31.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Measurement of the charge ratio of atmospheric muons with the CMS detector2010In: Phys. Lett., Vol. B692, p. 83-104Article in journal (Refereed)
• 32.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Measurement of the Isolated Prompt Photon Production Cross Section in $pp$ Collisions at $\sqrts = 7$ TeV2011In: Phys. Rev. Lett., Vol. 106Article in journal (Refereed)
• 33.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Measurement of the Muon Stopping Power in Lead Tungstate2010In: JINST, Vol. 5Article in journal (Refereed)
• 34.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Measurements of Inclusive $W$ and $Z$ Cross Sections in $pp$ Collisions at $\sqrts=7$ TeV2011In: JHEP, Vol. 01Article in journal (Refereed)
• 35.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Observation and studies of jet quenching in PbPb collisions at nucleon-nucleon center-of-mass energy = 2.76 TeV2011In: Phys. Rev., Vol. C84Article in journal (Refereed)
• 36.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Observation of Long-Range Near-Side Angular Correlations in Proton-Proton Collisions at the LHC2010In: JHEP, Vol. 09Article in journal (Refereed)
• 37.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Performance of CMS Muon Reconstruction in Cosmic-Ray Events2010In: JINST, Vol. 5Article in journal (Refereed)
• 38.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Performance of the CMS Cathode Strip Chambers with Cosmic Rays2010In: JINST, Vol. 5Article in journal (Refereed)
• 39.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Performance of the CMS Level-1 Trigger during Commissioning with Cosmic Ray Muons2010In: JINST, Vol. 5Article in journal (Refereed)
• 40.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Prompt and non-prompt $J/ψ$ production in $pp$ collisions at $\sqrts=7$ TeV2011In: Eur. Phys. J., Vol. C71Article in journal (Refereed)
• 41.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for a Heavy Bottom-like Quark in $pp$ Collisions at $\sqrts = 7$ TeV2011In: Phys. Lett., Vol. B701, p. 204-223Article in journal (Refereed)
• 42.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for a heavy gauge boson $W$ ’ in the final state with an electron and large missing transverse energy in $pp$ collisions at $\sqrts=7$ TeV2011In: Phys. Lett., Vol. B698, p. 21-39Article in journal (Refereed)
• 43.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for a $W^\prime$ boson decaying to a muon and a neutrino in $pp$ collisions at $\sqrts = 7$ TeV2011In: Phys. Lett., Vol. B701, p. 160-179Article in journal (Refereed)
• 44.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for Dijet Resonances in 7 TeV pp Collisions at CMS2010In: Phys. Rev. Lett., Vol. 105Article in journal (Refereed)
• 45.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for Heavy Stable Charged Particles in $pp$ collisions at $\sqrts=7$ TeV2011In: JHEP, Vol. 03Article in journal (Refereed)
• 46.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for Microscopic Black Hole Signatures at the Large Hadron Collider2011In: Phys. Lett., Vol. B697, p. 434-453Article in journal (Refereed)
• 47.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for Pair Production of First-Generation Scalar Leptoquarks in $pp$ Collisions at $\sqrts=7$ TeV2011In: Phys. Rev. Lett., Vol. 106Article in journal (Refereed)
• 48.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for Pair Production of Second-Generation Scalar Leptoquarks in $pp$ Collisions at $\sqrts=7$ TeV2011In: Phys. Rev. Lett., Vol. 106Article in journal (Refereed)
• 49.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for Physics Beyond the Standard Model in Opposite-Sign Dilepton Events at $\sqrts = 7$ TeV2011In: JHEP, Vol. 06Article in journal (Refereed)
• 50.
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
Search for Quark Compositeness with the Dijet Centrality Ratio in $pp$ Collisions at $\sqrts=7$ TeV2010In: Phys. Rev. Lett., Vol. 105Article in journal (Refereed)
12 1 - 50 of 60
Cite
Citation style
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• ieee
• modern-language-association
• vancouver
• Other style
More styles
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