624 research outputs found
Measurement of the cross-section for W boson production in association with b-jets in pp collisions at √s=7 TeV with the ATLAS detector
No full textThis paper reports a measurement of the W +b-jets (W +b+ X and W + bb¯ +X) production cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC. These results are based on data corresponding to an integrated luminosity of 4.6 fb−1, collected with the ATLAS detector. Cross-sections are presented as a function of jet multiplicity and of the transverse momentum of the leading b-jet for both the muon and electron decay modes of the W boson. The W +b-jets cross-section, corrected for all known detector effects, is quoted in a limited kinematic range. Combining the muon and electron channels, the fiducial cross-section for W +b-jets is measured to be 7.1 ± 0.5 (stat) ± 1.4 (syst) pb, consistent with the next-to-leading order QCD prediction, corrected for non-perturbative and double-parton interactions (DPI) contributions, of 4.70 ± 0.09 (stat) +0.60−0.49 (scale) ±0.06 (PDF) ±0.16 (non-pert) +0.52−0.38 (DPI) pb
Measurement of the production of a W boson in association with a charm quark in pp collisions at s√ = 7 TeV with the ATLAS detector
No full textThe production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + + c¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯ quark asymmetry
Príčiny úbytku Maďarov na Slovensku v období 1991-2011
No full textHungarians are the largest autochthonous national minority of the Slovak republic. Their number and proportion is steadily decreasing. The reduction of Hungarian population is caused by interactions between the following four factors: anonyme nationality, hidden migration, natural decline and as- similation. The strongest factor is the assimilation by the author understood as a change of national identity
Status of the Atlas Liquid Argon Calorimeter and its Performance after Three Years of LHC Operation
No full textThe ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo- rapidity region up to 3.2, as well as for hadronic calorimetry in the range 1.5-4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response without any gap. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at approximately 89 K. After installation in 2004-2006, the calorimeters were extensively commissioned over the three-year period prior to first collisions in 2009, using cosmic rays and single LHC beams. Since then, around 27 fb-1 of data have been collected at centre of mass energies of 7-8 TeV. During all these stages, the calorimeter has been operating almost optimally, with performance very close to specifications. The talk will cover all aspects of these first years of operation, including the calibration efforts and the data quality assessment procedure. The excellent performance achieved will also be briefly reviewed, especially in the context of the recently announced discovery of the Higgs boson
Performance of jet substructure techniques for large-R jets in proton-proton collisions at root s=7 TeV using the ATLAS detector
No full textThis paper presents the application of a variety of techniques to study jet substructure. The performance of various modified jet algorithms, or jet grooming techniques, for several jet types and event topologies is investigated for jets with transverse momentum larger than 300 GeV. Properties of jets subjected to the mass-drop filtering, trimming, and pruning algorithms are found to have a reduced sensitivity to multiple proton-proton interactions, are more stable at high luminosity and improve the physics potential of searches for heavy boosted objects. Studies of the expected discrimination power of jet mass and jet substructure observables in searches for new physics are also presented. Event samples enriched in boosted W and Z bosons and top-quark pairs are used to study both the individual jet invariant mass scales and the efficacy of algorithms to tag boosted hadronic objects. The analyses presented use the full 2011 ATLAS dataset, corresponding to an integrated luminosity of 4.7 +/- 0.1 fb(-1) from proton-proton collisions produced by the Large Hadron Collider at a centre-of-mass energy of root s = 7 TeV
Optimizing the Energy Measurement of the ATLAS Electromagnetic Calorimeter
No full textThis PhD-thesis addresses the calibration of the ATLAS electromagnetic calorimeter. ATLAS is a high-energy physics experiment at the Large Hadron Collider (LHC) which is currently under construction at CERN in Geneva. LHC and ATLAS are foreseen to start up in 2007. In summer 2004, an extensive beam-test was carried out. This means that individual detector modules are exposed to a particle beam of known energy in order to verify the detector performance. At this occasion, all ATLAS subdetectors where operated together for the first time. The thesis contains a comprehensive description of the ATLAS electromagnetic calorimeter, the reconstruction software and the test-beam experiment that was carried out at CERN in 2004. Furthermore, the physics of the electromagnetic shower is discussed in detail. Data from the test beam as well as a detailed Monte-Carlo Simulation are used to develop a novel energy-reconstruction method for the ATLAS EM Calorimeter that achieves an excellent energy resolution (sampling term ~11%) as well as a very good linearity (<0.4%). Data taken during the beam test is also used to verify the accuracy of the simulation and to test the new energy-reconstruction method
Search for pair production of massive particles decaying into three quarks with the ATLAS detector in root s=7 TeV pp collisions at the LHC
No full textATLAS Collaboration Contributor: P. JacksonA search is conducted for hadronic three-body decays of a new massive coloured particle in √s=7 TeV pp collisions at the LHC using an integrated luminosity of 4.6 fb−1 collected by the ATLAS detector. Supersymmetric gluino pair production in the context of a model with R-parity violation is used as a benchmark scenario. The analysis is divided into two search channels, each optimised separately for their sensitivity to high-mass and low-mass gluino production. The first search channel uses a stringent selection on the transverse momentum of the six leading jets and is performed as a counting experiment. The second search channel focuses on low-mass gluinos produced with a large boost. Large-radius jets are selected and the invariant mass of each of the two leading jets is used as a discriminant between the signal and the background. The results are found to be consistent with Standard Model expectations and limits are set on the allowed gluino mass.The ATLAS collaboratio
Clinique psychanalytique du caractère
No full text@Cette thèse s'est donnée pour but d'étudier la question du traitement du caractère dans l'oeuvre de Freud et de ses successeurs directs (W. Reich, K. Abraham, F. Alexander, E. lover, R. Sterba, O. Fenichel, H. Deutsch), pour en étudier le prolongement chez les auteurs contemporains (Diatkine, Lowenstein, Langer, Kestemberg, Lampl de Groot d'une part, J. Lacan de l'autre). Le caractère apparaît comme un concept complexe, situé aux limites de la théorie et de la pratique.ST DENIS-BU PARIS8 (930662101) / SudocSudocFranceF
The development of an assessment tool to gather evidence and evaluate the progress of performance skills of students in the Edgerton High School Band
No full textProject chair, Dr. Glenn C. Hayes.Because of the block schedule and the lack of certain basic music skills among the incoming band students at Edgerton High School, it is necessary to create a system to help students establish their basic performance skills. The purpose of this project is to design a set of assessment tools that will help students define and perform basic musical skills. A series of quarterly study sheets allows the student to study scales, rhythms, tone, and expression in a progressive manner through all grade levels. The student is required to master each form and the skill level demonstrated serves as a portion of his or her final grade. It is also necessary to have a way to assess the students’ skills. This project uses literature and methods from a variety of sources to develop a set of tools that will accomplish both of these objectives.
This project focuses on the four areas of skills basic to musical performance on a musical instrument including scales and arpeggios, rhythm, tone, and expression. The study of scales, arpeggios, and rhythm has been systematically designed to increase the technical skill of students on their instruments. Students will have studied the major, minor, and chromatic scales and arpeggios in a systematic method over a four-year course of study. Each term for four years (16 terms), the student will have studied one major scale, the relative minor scale, arpeggios, and the chromatic scale. In addition, the student will have studied a specific rhythm pattern each term. The chromatic scale study has been coordinated to the rhythm study for each term to help reinforce the rhythm pattern. The rhythm patterns began with the easiest whole rhythms (whole, half, and quarter notes) and get progressively more difficult with each term.
In addressing tone quality, the teacher will have assigned a phrase of music from the literature studied by the band. The student will have performed the phrase with the best tone quality he/she can produce. A rubric has been developed to assess the student’s level of tone production quality and to help the student begin to identify the qualities of an excellent tone.
Musical expression has been addressed in two manners. The first has been through a demonstration of expression during the same performance of the tone quality assignment. Students have been assessed on a rubric similar to the one designed for tone quality. In addition, the student has been presented with a blank phrase of music. The student then adds expression markings that they feel are appropriate and performs the excerpt. Again, a rubric has been designed to assess the work of the student
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