Download or read book Measurements of the Top quark Decay Width and Mass at CDF Using the Template Method written by and published by . This book was released on 2012 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the top quark decay width and mass are presented using the tt events produced in p p collisions at Fermilab's Tevatron collider and collected by the CDF II detector. A data sample corresponding to 4.3 fb-1 of integrated luminosity is used for the top quark width measurement. Two estimators, the reconstructed top quark mass and the mass of hadronically decaying W boson that comes from the top-quark decay are reconstructed for each event and compared with templates of different input top quark widths and deviations from nominal CDF jet energy scale ([Delta]JES) to perform a simultaneous fit for both parameters. [Delta]JES is used for the in situ calibration of the jet energy scale at CDF. By applying a Feldman-Cousins limit-setting approach, we establish an upper limit at 95% confidence level (CL) of [Gamma]top
Download or read book Measurements of the Top quark Decay Width and Mass at CDF Using the Template Method written by Jian Tang and published by . This book was released on 2012 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the top quark decay width and mass are presented using the tt events produced in p p collisions at Fermilab's Tevatron collider and collected by the CDF II detector.
Download or read book Measurement of the Top Quark Mass at CDF Using the Template Method in the Lepton Jets Channel written by Jahred Adelman and published by . This book was released on 2008 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Top Quark Mass Measurement Using the Template Method at CDF written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the top quark mass in the lepton+jets and dilepton channels of t{bar t} decays using the template method. The data sample corresponds to an integrated luminosity of 5.6 fb−1 of p{bar p} collisions at Tevatron with √s = 1.96 TeV, collected with the CDF II detector. The measurement is performed by constructing templates of three kinematic variables in the lepton+jets and two kinematic variables in the dilepton channel. The variables are two reconstructed top quark masses from different jets-to-quarks combinations and the invariant mass of two jets from the W decay in the lepton+jets channel, and a reconstructed top quark mass and m{sub T2}, a variable related to the transverse mass in events with two missing particles, in the dilepton channel. The simultaneous fit of the templates from signal and background events in the lepton+jets and dilepton channels to the data yields a measured top quark mass of M{sub top} = 172.1 ± 1.1 (stat) ± 0.9 (syst) GeV/c2.
Download or read book Measurement of the Top Quark Mass at CDF Using the Template Method in the Lepton Jets Channel written by and published by . This book was released on 2008 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the top quark mass in p{bar p} collisions at (square root)s = 1.96 TeV is presented. The analysis uses a template method, in which the overconstrained kinematics of the Lepton+Jets channel of the t{bar t} system are used to measure a single quantity, the reconstructed top quark mass, that is strongly correlated with the true top quark mass. in addition, the dijet mass of the hadronically decaying W boson is used to constrain in situ the uncertain jet energy scale in the CDF detector. Two-dimensional probability density functions are derived using a kernel density estimate-based machinery. Using 1.9 fb−1 of data, the top quark mass is measured to be 171.8{sub -1.9}{sup +1.9}(stat.) ± 1.0(syst.)GeV/c2.
Download or read book CDF Measurement of the Top Quark Mass in the Lepton Jets Channel Using the Multivariate Template Method written by John Freeman and published by . This book was released on 2004 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors measure the mass of the top quark using 162 pb{sup -1} of data collected by the CDF experiment at FNAL in Run II. The decay chain t{bar t} {yields} bq{bar q}{bar b}lv is studied using a novel technique called the Multivariate Template Method (MTM). Using this technique they obtain a result of M{sub top} = 179.6{sub -6.3}{sup +6.4} {+-} 6.8 GeV/c{sup 2} for the top quark.
Download or read book Measurement of the Top Quark Mass Using the Template Method in the Lepton Plus Jets Channel with in Situ W J J Calibration at CDF II written by T. Maruyama and published by . This book was released on 2006 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report an updated measurement of the top quark mass in the lepton plus jets channel of t{bar t} events from p{bar p} collisions at {radical}s = 1.96 TeV. This measurement uses a dataset with integrated luminosity of 680 pb{sup -1}, containing 360 t{bar t} candidates separated into four subsamples. A top quark mass is reconstructed for each event by using energy and momentum constraints on the top quark pair decay products. We also employ the reconstructed mass of hadronic W boson decays W {yields} jj to constrain in situ the largest systematic uncertainty of the top quark mass measurement: the jet energy scale. Monte Carlo templates of the reconstructed top quark and W boson mass are produced as a function of the true top quark mass and the jet energy scale. The distribution of reconstructed top quark and W boson mass in the data are compared to the Monte Carlo templates using a likelihood fit to obtain: M{sub top} = 173.4 {+-} 2.8 GeV/c{sup 2}.
Download or read book Measurement of the Top Quark Mass at CDF Using the eutrino Phi Weighting Template Method on a Lepton Plus Isolated Track Sample written by and published by . This book was released on 2009 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the top quark mass with t{bar t} dilepton events produced in p{bar p} collisions at the Fermilab Tevatron (√s = 1.96 TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9 fb−1, are selected as t{bar t} candidates. To account for the unconstrained event kinematics, we scan over the phase space of the azimuthal angles (?{sub {nu}1},?{sub {nu}2}) of neutrinos and reconstruct the top quark mass for each?{sub {nu}1},?{sub {nu}2} pair by minimizing a?2 function in the t{bar t} dilepton hypothesis. We assign?2-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated t{bar t} and background events, and parameterized in order to provide continuous probability density functions. A likelihood fit to the mass distribution in data as a weighted sum of signal and background probability density functions gives a top quark mass of 165.5{sub -3.3}{sup +3.4}(stat.)±3.1(syst.) GeV/c2.
Download or read book Top Quark Mass Measurement Using the Template Method in the Lepton Jets Channel at CDF II written by and published by . This book was released on 2005 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Top Quark Physics at Hadron Colliders written by Arnulf Quadt and published by Springer Science & Business Media. This book was released on 2007-08-16 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This will be a required acquisition text for academic libraries. More than ten years after its discovery, still relatively little is known about the top quark, the heaviest known elementary particle. This extensive survey summarizes and reviews top-quark physics based on the precision measurements at the Fermilab Tevatron Collider, as well as examining in detail the sensitivity of these experiments to new physics. Finally, the author provides an overview of top quark physics at the Large Hadron Collider.
Download or read book Measurement of the Top Quark Mass Using Template Methods on Dilepton Events in P Anti p Collisions at S written by and published by . This book was released on 2006 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors describe a measurement of the top quark mass from events produced in p{bar p} collisions at a center-of-mass energy of 1.96 TeV, using the Collider Detector at Fermilab. They identify t{bar t} candidates where both W bosons from the top quarks decay into leptons (e?,??, or??) from a data sample of 360 pb−1. The top quark mass is reconstructed in each event separately by three different methods, which draw upon simulated distributions of the neutrino pseudorapidity, t{bar t} longitudinal momentum, or neutrino azimuthal angle in order to extract probability distributions for the top quark mass. For each method, representative mass distributions, or templates, are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. A likelihood fit incorporating these parameterized templates is then performed on the data sample masses in order to derive a final top quark mass. Combining the three template methods, taking into account correlations in their statistical and systematic uncertainties, results in a top quark mass measurement of 170.1 ± 6.0(stat.) ± 4.1(syst.) GeV/c2.
Download or read book Measurement of the Top Quark Mass Using Template Methods on Dilepton Events in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2006 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors describe a measurement of the top quark mass from events produced in p{bar p} collisions at a center-of-mass energy of 1.96 TeV, using the Collider Detector at Fermilab. They identify t{bar t} candidates where both W bosons from the top quarks decay into leptons (e[nu], [mu][nu], or [tau][nu]) from a data sample of 360 pb−1. The top quark mass is reconstructed in each event separately by three different methods, which draw upon simulated distributions of the neutrino pseudorapidity, t{bar t} longitudinal momentum, or neutrino azimuthal angle in order to extract probability distributions for the top quark mass. For each method, representative mass distributions, or templates, are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. A likelihood fit incorporating these parameterized templates is then performed on the data sample masses in order to derive a final top quark mass. Combining the three template methods, taking into account correlations in their statistical and systematic uncertainties, results in a top quark mass measurement of 170.1 ± 6.0(stat.) ± 4.1(syst.) GeV/c2.
Download or read book Top Quark Mass Measurement written by and published by . This book was released on 2008 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark is the heaviest elementary particle. Its mass is one of the fundamental parameters of the standard model of particle physics, and an important input to precision electroweak tests. This thesis describes three measurements of the top-quark mass in the dilepton decay channel. The dilepton events have two neutrinos in the final state; neutrinos are weakly interacting particles that cannot be detected with a multipurpose experiment. Therefore, the signal of dilepton events consists of a large amount of missing energy and momentum carried off by the neutrinos. The top-quark mass is reconstructed for each event by assuming an additional constraint from a top mass independent distribution. Template distributions are constructed from simulated samples of signal and background events, and parametrized to form continuous probability density functions. The final top-quark mass is derived using a likelihood fit to compare the reconstructed top mass distribution from data to the parametrized templates. One of the analyses uses a novel technique to add top mass information from the observed number of events by including a cross-section-constraint in the likelihood function. All measurements use data samples collected by the CDF II detector.
Download or read book Measurements of the Top Quark Mass and Decay Width with the D0 Detector written by and published by . This book was released on 2011 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark discovery in 1995 at Fermilab is one of the major proofs of the standard model (SM). Due to its unique place in SM, the top quark is an important particle for testing the theory and probing for new physics. This article presents most recent measurements of top quark properties from the D0 detector. In particular, the measurement of the top quark mass, the top antitop mass difference and the top quark decay width. The discovery of the top quark in 1995 confirmed the existence of a third generation of quarks predicted in the standard model (SM). Being the heaviest elementary particle known, the top quark appears to become an important particle in our understanding of the standard model and physics beyond it. Because of its large mass the top quark has a very short lifetime, much shorter than the hadronization time. The predicted lifetime is only 3.3 · 10−25s. Top quark is the only quark whose properties can be studied in isolation. A Lorentz-invariant local Quantum Field Theory, the standard model is expected to conserve CP. Due to its unique properties, the top quark provides a perfect test of CPT invariance in the standard model. An ability to look at the quark before being hadronized allows to measure directly mass of the top quark and its antiquark. An observation of a mass difference between particle and antiparticle would indicate violation of CPT invariance. Top quark through its radiative loop correction to the W mass constrains the mass of the Higgs boson. A precise measurement of the top quark mass provides useful information to the search of Higgs boson by constraining its region of possible masses. Another interesting aspect is that the top quark's Yukawa coupling to the Higgs boson is very close to unity (0.996 ± 0.006). That implies it may play a special role in the electroweak symmetry breaking mechanism.
Download or read book Direct Measurement of the Top quark Decay Width with the ATLAS Detector written by Tomas Dado and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark is the heaviest known elementary particle. Due to its large mass, the top quark decays before it forms bound states. This makes the top quark a unique particle in the Standard Model. Precise measurements of its properties could be used as tests of the consistency of the Standard Model and potential deviations could point to physics Beyond the Standard Model. This thesis deals with the direct measurement of the top-quark decay width using data collected in proton-proton collisions at centre-of-mass energies of 8 and 13 TeV with the ATLAS detector at the Large Hadron Collider. T...
Download or read book Measurement of the Top Quark Mass with in Situ Jet Energy Scale Calibration Using Hadronic W Boson Decays at CDF II written by Jean-François Arguin and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the top quark mass with the upgraded Collider Detector at Fermilab (CDF-II). The top quarks are produced in pairs (tt−) in proton-antiproton collisions with a center-of-mass energy of 1.96 TeV. Each top quark decays to a W boson and a bottom quark. We select candidate events in which one W boson decays hadronically and the other decays to an electron or a muon and its associated neutrino. The data sample, which corresponds to an integrated luminosity of 318 pb-1, contains 138 tt− candidates. A top quark mass is reconstructed for each event by placing energy and momentum constraints on the top quark pair decay products. We also employ the reconstructed mass of the hadronic W boson decays W & rarr; jj to constrain in situ the largest systematic uncertainty of the top quark mass measurement, the jet energy scale. Monte Carlo templates of the reconstructed top quark and W boson mass are produced as a function of the top quark mass and the jet energy scale. The distribution of reconstructed top quark and W boson mass in the data are compared to the Monte Carlo templates using a likelihood fit to obtain Mtop = 173.5+3.9-3.8 GeV/c2. This constitutes the most precise measurement of the top quark mass to date. This measurement can be used to constrain the mass of the Higgs boson, a central particle in the Standard Model of particle physics that has yet to be observed. We also demonstrate that this new technique reduces naturally the jet, energy scale uncertainty as more data is accumulated and thus provides the capability to measure Mtop with an uncertainty of 2 GeV/c2 or better by the end of the CDF-II experiment.
Download or read book A Measurement of the Top Quark Mass with a Matrix Element Method written by Adam Paul Gibson and published by . This book was released on 2006 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
