A measurement of the ratio of the inclusive 3-jet to 2-jet cross sections as a function of the total jet transverse momentum, H sub(T), in the range 0.2<H sub(T)<2.5 TeV is presented. The data have ...been collected at a proton-proton centre-of-mass energy of 7 TeV with the CMS detector at the LHC, and correspond to an integrated luminosity of 36 pb super(-1). Comparisons are made between the data and the predictions of different QCD-based Monte Carlo models for multijet production. All models considered in this study are consistent with the data for H sub(T)>0.5 TeV. This measurement extends to an H sub(T) range that has not been explored before.
A measurement of W gamma and Z gamma production in proton-proton collisions at inline imageinline image is presented. Results are based on a data sample recorded by the CMS experiment at the LHC, ...corresponding to an integrated luminosity of 36 pb super(-1. The electron and muon decay channels of the W and Z are used. The total cross sections are measured for photon transverse energy inline imageinline image and spatial separation from charged leptons in the plane of pseudorapidity and azimuthal angle Delta R(l, gamma )0.7, and with an additional dilepton invariant mass requirement of M) sub(l)l50 GeV for the Z gamma process. The following cross section times branching fraction values are found: inline imageinline image and inline imageinline image. These measurements are in agreement with standard model predictions. The first limits on anomalous WW gamma , ZZ gamma , and Z gamma gamma trilinear gauge couplings at inline imageinline image are set.
Test of a CMS MSGC tracker prototype in a high-intensity hadron beam Abbaneo, D.; Albert, E.; Angelini, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1998, Letnik:
409, Številka:
1-3
Journal Article
Recenzirano
A set of CMS MicroStrip Gas Chambers (MSGC) was exposed to a high-intensity 3GeV/c pion beam at a CERN PS facility for a period of two weeks. The performance of the detectors is reported in terms of ...stability of efficiency and response to minimum ionising particles as well as to more heavily ionising fragments generated by nuclear interactions.
The Resistive Plate Chambers M. Abbrescia, et al., Nucl. Instr. and Meth. A 550 (2005) 116 are used in the CMS experiment CMS Collaboration, The CMS experiment at the CERN LHC 2008, J. Inst. 3 (2008) ...S08004 as a dedicated muon trigger both in barrel and endcap system. About
4000
m
2
of double gap RPCs have been produced and have been installed in the experiment since more than one and half Years. The full barrel system and a fraction of the endcaps have been monitored to study dark current behaviour and system stability, and have been extensively commissioned with Cosmic Rays collected by the full CMS experiment.
A measurement of the underlying activity in scattering processes with transverse momentum scale in the GeV region is performed in proton-proton collisions at sqrt(s) = 0.9 TeV, using data collected ...by the CMS experiment at the LHC. Charged hadron production is studied with reference to the direction of a leading object, either a charged particle or a set of charged particles forming a jet. Predictions of several QCD-inspired models as implemented in PYTHIA are compared, after full detector simulation, to the data. The models generally predict too little production of charged hadrons with pseudorapidity eta < 2, p_T > 0.5 GeV/c, and azimuthal direction transverse to that of the leading object.
The MICROMEGEM detector Bouhali, O.; De Lentdecker, G.; Dewèze, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2001, Letnik:
459, Številka:
1
Journal Article
Recenzirano
This article introduces the MICROMEGEM detector, a position-sensitive proportional gas counter produced using advanced Printed Circuit Board (PCB) technology. The detector is equipped with a Gas ...Electron Multiplier (GEM) foil placed
50
μm
above a plane of pick-up strips. The GEM produces a first gas amplification which is extended below the GEM foil by applying a strong electric field between the strips and the lower electrode of the GEM. The array of strips is used for read-out to obtain 1-D positional information. We present results on the gas gain, the energy resolution and the rate capability. The behaviour in an intense beam of
300
MeV/c
pions in presence of heavily ionizing particles has also been investigated.
Simulation study of silicon and gaseous tracking detectors Beaumont, W; Beckers, T; De Lentdecker, G ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2002, Letnik:
478, Številka:
1
Journal Article
Recenzirano
The performance of microstrip gaseous counters (MSGC, MSGC + GEM) and silicon microstrip sensors has been studied in view of their use in high luminosity tracking applications. Simulations of signal ...development in the detectors and subsequent signal treatment in the readout electronics were performed. The simulation results are compared with experimental data obtained in test beams.
A small series production of detector modules made of MicroStrip Gas Counters (MSGC) and a Gas Electron Multiplier (GEM) foil has been exposed to a high-intensity hadron beam. We report about the ...reproductibility and stability of the detector responses and about the occurrence and consequences of discharges in the detector. The interdependence of the four voltage differences used in the detector has been studied by simulation and with X-ray measurements. Rate dependence of the signal amplitude is observed. The behaviour of the MSGC+GEM is compared to that of a state-of-the-art MSGC. Influence of various parameters on the detector response is investigated.
Operation of microstrip gas counters with DME-based gas mixtures Bouhali, O; Udo, F; Van Doninck, W ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/1998, Letnik:
413, Številka:
1
Journal Article
Recenzirano
This paper reports on the operation of MicroStrip Gas Counters (MSGC) with several dimethylether (DME)-based gas mixtures. We present measurements of signal amplitude, detection efficiency and ...spatial resolution for minimum ionizing particles. We also show measurements of electron drift velocity and transverse diffusion coefficient in the counting gases considered. These results are discussed regarding the use of MSGC’s for tracking at high-energy physics experiments that have to deal with high particle rates.
The use of distance variables expressing the likelihood of species occurrence at a given site in relation to the distance to observed species presence is demonstrated to improve species distribution ...models, especially when combined with environmental variables which relate species occurrence to the environmental habitat characteristics. In this study we developed models to predict the spatio-temporal distribution of Culicoides imicola, which is the main transmission vector for the bluetongue virus in the Mediterranean region. We investigated (i) the importance of the environmental habitat characterization by means of bioclimatic variables, (ii) the effect of different distance variables to model the dispersal process, and (iii) the suitability of two different parameter identification procedures to determine the distance variables for species distribution modeling. Results showed that niche-based species distribution models, which only use environmental data, could estimate the occurrence of Culicoides imicola accurately, given that environmental data of the period of high species abundance (April until October) was included. The use of these models may therefore be hampered for predictive risk assessment aiming to estimate the probabilities and magnitude of undesired effects caused by the occurrence of C. imicola. Species distribution models accounting for species dispersal in addition to the environmental habitat characteristics, i.e. hybrid models, did provide accurate predictions of C. imicola distributions well before the onset of the season of high species abundance. A Gaussian or negative exponential function of the distance to presence locations was most suitable to model insect dispersal. The enhanced predictive capacity of these models potentially leads towards an increased model applicability in risk assessment and disease control.
•We modeled the distribution of Culicoides imicola in the Mediterranean region.•Niche based models were compared with hybrid distribution models.•Models were evaluated using cross-validation and independent data.•Inclusion of spatial autocorrelation increased the model performance significantly.•This model has a better potential for risk assessment and preventive disease control.
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