37 research outputs found
Vous cherchez ? Anne-Sylvie Giolo-Nicollerat
No full textAnne-Sylvie Giolo-Nicollerat is a doctor in physics, graduate of the EPFZ. She works at CERN as a particle physicist (1 page
Electron reconstruction and electroweak processes as tools to achieve precision measurements at a hadron collider: from CDF to CMS
No full textTop Background to SM Higgs Searches in the W^{+}W^{-} \to l\nul\overline{\nu} Decay Mode at CMS
No full textThe top quark and its properties within and beyond the Standard Model will be extensively studied at the incoming Large Hadron Collider. Nonetheless the top quark will play the role of the main background for most of the Higgs and new physics searches. In this paper the top as a background to H=>WW=>2l2nu Higgs discovery channel will be studied. The current status of the Monte Carlo tools for t-tbar and single top simulation will be presented. Finally the problem on how to evaluate the top background from the data will be addressed and the related systematics will be discussed.The top quark and its properties within and beyond the Standard Model will be extensively studied at the incoming Large Hadron Collider. Nonetheless the top quark will play the role of the main background for most of the Higgs and new physics searches. In this paper the top as a background to H=>WW=>2l2nu Higgs discovery channel will be studied. The current status of the Monte Carlo tools for t-tbar and single top simulation will be presented. Finally the problem on how to evaluate the top background from the data will be addressed and the related systematics will be discussed
Standard Model Higgs Discovery Potential of CMS in Channel
No full textThe discovery potential of the CMS detector for the Standard Model Higgs boson in the H->WW->lnulnu channel is assessed using a full detector simulation. Sources of systematic uncertainties as well as methods to determine backgrounds from data are discussed. If the Standard Model Higgs boson has a mass between 150GeV and 180GeV, it should be observed with a significance of more than 5 sigma with a luminosity of about 10fb-1
Systematic uncertainties of the top background in the H->WW channel
No full textThe ttbar process is one of the main backgrounds for the H->WW->lnulnu signal search. The simulation of this background as well as an estimation of its contribution to the total systematic error for this Higgs search will be studied in detail. For this, the predictions of the PYTHIA, HERWIG, TopREX and MC@NLO Monte Carlos are compared in order to estimate the effect of different showering programs and of the spin correlations. Furthermore, the question of how to include NLO corrections will be addressed and the simulation of single top background at NLO discussed. In order to extrapolate the ttbar background to the Higgs signal region, once data is available, different normalization methods will be proposed and compared. The experimental uncertainties coming from different normalization processes will be estimated using a full CMS simulation
Les Houches Physics at TeV Colliders 2005, Standard Model and Higgs working group: Summary report
No full textThis Report summarises the activities of the "SM and Higgs" working group for the Workshop "Physics at TeV Colliders", Les Houches, France, 2-20 May, 2005. On the one hand, we performed a variety of experimental and theoretical studies on standard candles (such as W, Z, and ttbar production), treating them either as proper signals of known physics, or as backgrounds to unknown physics; we also addressed issues relevant to those non-perturbative or semi-perturbative ingredients, such as Parton Density Functions and Underlying Events, whose understanding will be crucial for a proper simulation of the actual events taking place in the detectors. On the other hand, several channels for the production of the Higgs, or involving the Higgs, have been considered in some detail. The report is structured into four main parts. The first one deals with Standard Model physics, except the Higgs. A variety of arguments are treated here, from full simulation of processes constituting a background to Higgs production, to studies of uncertainties due to PDFs and to extrapolations of models for underlying events, from small- issues to electroweak corrections which may play a role in vector boson physics. The second part of the report treats Higgs physics from the point of view of the signal. In the third part, reviews are presented on the current status of multi-leg, next-to-leading order and of next-to-next-to-leading order QCD computations. Finally, the fourth part deals with the use of Monte Carlos for simulation of LHC physics
Stand-alone cosmic muon reconstruction before installation of the CMS silicon strip tracker
No full textThis is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2009 IOPThe subsystems of the CMS silicon strip tracker were integrated and commissioned at the Tracker Integration Facility (TIF) in the period from November 2006 to July 2007. As part of the commissioning, large samples of cosmic ray data were recorded under various running conditions in the absence of a magnetic field. Cosmic rays detected by scintillation counters were used to trigger the readout of up to 15 % of the final silicon strip detector, and over 4.7 million events were recorded. This document describes the cosmic track reconstruction and presents results on the performance of track and hit reconstruction as from dedicated analyses.This work was supported by: the Austrian
Federal Ministry of Science and Research; the Belgium Fonds de la Recherche Scientifique and Fonds voorWetenschappelijk
Onderzoek; the Academy of Finland and Helsinki Institute of Physics; the Institut National de Physique Nucleaire et de Physique des Particules / CNRS, France; the Bundesministerium fur Bildung und Forschung, Germany; the Istituto Nazionale di Fisica Nucleare, Italy; the Swiss Funding Agencies; the Science and Technology Facilities Council, UK; the US Department of Energy, and National Science Foundation. Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation
Performance studies of the CMS strip tracker before installation
No full textThis is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2009 IOPIn March 2007 the assembly of the Silicon Strip Tracker was completed at the Tracker Integration Facility at CERN. Nearly 15% of the detector was instrumented using cables, fiber optics, power supplies, and electronics intended for the operation at the LHC. A local chiller was used to circulate the coolant for low temperature operation. In order to understand the efficiency and alignment of the strip tracker modules, a cosmic ray trigger was implemented. From March through July 4.5 million triggers were recorded. This period, referred to as the Sector Test, provided practical experience with the operation of the Tracker, especially safety, data acquisition, power, and cooling systems. This paper describes the performance of the strip system during the Sector Test, which consisted of five distinct periods defined by the coolant temperature. Significant emphasis is placed on comparisons between the data and results from Monte Carlo studies.This work was supported by: the Austrian
Federal Ministry of Science and Research; the Belgium Fonds de la Recherche Scientifique and Fonds voorWetenschappelijk
Onderzoek; the Academy of Finland and Helsinki Institute of Physics; the Institut National de Physique Nucleaire et de Physique des Particules / CNRS, France; the Bundesministerium f¨ur Bildungund Forschung, Germany; the Istituto Nazionale di Fisica Nucleare, Italy; the Swiss Funding Agencies; the Science and Technology Facilities Council, UK; the US Department of Energy, and National Science Foundation. Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation
The CMS Tracker operation and performance at the Magnet Test and Cosmic Challenge
No full textDuring summer 2006 a fraction of the CMS silicon strip tracker was operated in a comprehensive slice test called the Magnet Test and Cosmic Challenge (MTCC). At the MTCC, cosmic rays detected in the muon chambers were used to trigger the readout of all CMS sub-detectors in the general data acquisition system and in the presence of the 4 T magnetic field produced by the CMS superconducting solenoid. This document describes the operation of the Tracker hardware and software prior, during and after data taking. The performance of the detector as resulting from the MTCC data analysis is also presented. © 2008 IOP Publishing Ltd and SISSA.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
First measurements of inclusive W and Z cross sections from Run II of the Fermilab Tevatron Collider
No full textWe report the first measurements of inclusive W and Z cross sections times leptonic branching ratios for p (p) over bar collisions at root s=1.96 TeV, based on their decays to electrons and muons. The data correspond to an integrated luminosity of 72 pb(-1) recorded with the CDF detector at the Fermilab Tevatron. We test e-mu universality in W decays, and we measure the ratio of leptonic W and Z rates from which the leptonic branching fraction B(W -> l nu) can be extracted as well as an indirect value for the total width of the W and the Cabibbo-Kobayashi-Maskawa matrix element, vertical bar V(cs)vertical bar
