Physics / Fizik
Permanent URI for this collectionhttps://hdl.handle.net/11147/6
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Article Citation - WoS: 41Citation - Scopus: 41Calibration of the Cms Drift Tube Chambers and Measurement of the Drift Velocity With Cosmic Rays(IOP Publishing Ltd., 2010) Demir, Durmuş Ali; Karapınar, GülerThis 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. © 2010 IOP Publishing Ltd and SISSA.Article Citation - WoS: 57Citation - Scopus: 46Commissioning and Performance of the Cms Silicon Strip Tracker With Cosmic Ray Muons(IOP Publishing Ltd., 2010) Demir, Durmuş Ali; Karapınar, GülerDuring autumn 2008, the Silicon Strip Tracker was operated with the full CMS experiment in a comprehensive test, in the presence of the 3.8 T magnetic field produced by the CMS superconducting solenoid. Cosmic ray muons were detected in the muon chambers and used to trigger the readout of all CMS sub-detectors. About 15 million events with a muon in the tracker were collected. The efficiency of hit and track reconstruction were measured to be higher than 99% and consistent with expectations from Monte Carlo simulation. This article details the commissioning and performance of the Silicon Strip Tracker with cosmic ray muons. © 2010 IOP Publishing Ltd and SISSA.Article Citation - WoS: 37Citation - Scopus: 41Performance of the Cms Cathode Strip Chambers With Cosmic Rays(IOP Publishing Ltd., 2010) Demir, Durmuş Ali; Karapınar, GülerThe Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47μm to 243μm. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns. © 2010 IOP Publishing Ltd and SISSA.Article Citation - WoS: 60Citation - Scopus: 41Commissioning and Performance of the Cms Pixel Tracker With Cosmic Ray Muons(IOP Publishing Ltd., 2010) Demir, Durmuş Ali; Karapınar, GülerThe pixel detector of the Compact Muon Solenoid experiment consists of three barrel layers and two disks for each endcap. The detector was installed in summer 2008, commissioned with charge injections, and operated in the 3.8 T magnetic field during cosmic ray data taking. This paper reports on the first running experience and presents results on the pixel tracker performance, which are found to be in line with the design specifications of this detector. The transverse impact parameter resolution measured in a sample of high momentum muons is 18 microns. © 2010 IOP Publishing Ltd and SISSA.Article Citation - WoS: 5Citation - Scopus: 31Performance of the Cms Drift Tube Chambers With Cosmic Rays(IOP Publishing Ltd., 2010) Demir, Durmuş Ali; Karapınar, GülerStudies 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.Article Citation - WoS: 86Citation - Scopus: 88Alignment of the Cms Silicon Tracker During Commissioning With Cosmic Rays(IOP Publishing Ltd., 2010) Demir, Durmuş Ali; Karapınar, GülerThe CMS silicon tracker, consisting of 1440 silicon pixel and 15 148 silicon strip detector modules, has been aligned using more than three million cosmic ray charged particles, with additional information from optical surveys. The positions of the modules were determined with respect to cosmic ray trajectories to an average precision of 3-4 microns RMS in the barrel and 3-14 microns RMS in the endcap in the most sensitive coordinate. The results have been validated by several studies, including laser beam cross-checks, track fit self-consistency, track residuals in overlapping module regions, and track parameter resolution, and are compared with predictions obtained from simulation. Correlated systematic effects have been investigated. The track parameter resolutions obtained with this alignment are close to the design performance.Article Citation - WoS: 33Citation - Scopus: 38Performance of the Cms Drift-Tube Chamber Local Trigger With Cosmic Rays(IOP Publishing Ltd., 2010) Demir, Durmuş Ali; Karapınar, GülerThe 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.Article Citation - WoS: 73Citation - Scopus: 76Commissioning of the Cms Experiment and the Cosmic Run at Four Tesla(IOP Publishing Ltd., 2010) Demir, Durmuş Ali; Karapınar, GülerThe 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.