Papers by ADALBERTO R ADALBERTO FRANCO AVILA
During autumn 2008, the Silicon Strip Tracker was operated with the full CMS experiment in a comp... more During 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. muon data were recorded in the presence of a solenoidal field up to the maximum design value of 4 T. The results from this period of data-taking are described elsewhere . Construction of the full SST was completed in 2007 and 15% of the full SST was commissioned and operated for several months prior to installation in the underground CMS experimental hall. The results of this period of stand-alone operation, known as the Slice Test, are also described elsewhere .
Commissioning studies of the CMS hadron calorimeter have identified sporadic uncharacteristic noi... more 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 ...
This paper describes the calibration procedure for the drift tubes of the CMS barrel muon system ... more 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.
The CMS Hadron Calorimeter in the barrel, endcap and forward regions is fully commissioned. Cosmi... more 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.
The CMS experiment uses self-triggering arrays of drift tubes in the barrel muon trigger to perfo... more The CMS experiment uses self-triggering arrays of drift tubes in the barrel muon trigger to perform the identification of the correct bunch crossing. The identification is unique only if the trigger chain is correctly synchronized. In this paper, the synchronization performed during an extended cosmic ray run is described and the results are reported. The random arrival time of cosmic ray muons allowed several synchronization aspects to be studied and a simple method for the fine synchronization of the Drift Tube Local Trigger at LHC to be developed. * See Appendix A for the list of collaboration members arXiv:0911.4904v2 [physics.ins-det] 12 Jan 2010
ABSTRACT The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS... more ABSTRACT The 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 47 microns to 243 microns. 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.
The pixel detector of the Compact Muon Solenoid experiment consists of three barrel layers and tw... more The 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.
The performance of muon reconstruction in CMS is evaluated using a large data sample of cosmic-ra... more The performance of muon reconstruction in CMS is evaluated using a large data sample of cosmic-ray muons recorded in 2008. Efficiencies of various high-level trigger, identification, and reconstruction algorithms have been measured for a broad range of muon momenta, and were found to be in good agreement with expectations from Monte Carlo simulation. The relative momentum resolution for muons crossing the barrel part of the detector is better than 1% at 10 GeV/c and is about 8% at 500 GeV/c, the latter being only a factor of two worse than expected with ideal alignment conditions. Muon charge misassignment ranges from less than 0.01% at 10 GeV/c to about 1% at 500 GeV/c.
This paper discusses the design and performance of the time measurement technique and of the sync... more 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.
The performance of the Local Trigger based on the drift-tube system of the CMS experiment has bee... more 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.
3, Tabla 3) (MIR 97-98, 201), así como fracturas, que suelen ser lineales (Figura 4). CAPUT SUCCE... more 3, Tabla 3) (MIR 97-98, 201), así como fracturas, que suelen ser lineales (Figura 4). CAPUT SUCCEDANEUM CEFALOLOHEMATOMA Edema de tejido celular subcutáneo Hemorragia subperióstica Inicio En el momento del parto Horas después del parto Respeta suturas No Sí Resolución En unos días 2 semanas-3 meses Piel suprayacente Equimótica a veces Normal Tabla 3. Diferencias entre caput succedaneum y cefalohematoma Figura 2. Caput succedaneum Q RECUERDA El cefalohematoma es una colección de sangre entre el periostio y el hueso; por el contrario, el capuí es un edema difuso del tejido celular subcutáneo. Cara: debe valorarse la simetría facial para descartar cuadros como la parálisis facial o bien la hipoplasia del músculo depresor del ángulo de la boca. La presencia de petequias o pequeñas hemorragias conjuntivales es normal, sobre todo en los partos vaginales. También hay que explorar los reflejos pupilares. La aparición de una leucocoria debe hacernos pensar en una catarata congénita, un retinoblastoma, una retinopatía de la prematuridad o una coriorretinitis severa. La no apertura de un ojo al alta debe hacernos sospechar glaucoma congénito y es una urgencia oftalmológica.
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Papers by ADALBERTO R ADALBERTO FRANCO AVILA