Measurement of the Top-quark Mass in the Lepton+jets Channel Using a Matrix Element Technique with the CDF II Detector
Title | Measurement of the Top-quark Mass in the Lepton+jets Channel Using a Matrix Element Technique with the CDF II Detector PDF eBook |
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Release | 2011 |
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Top Quark Mass Measurement in the Lepton + Jets Channel Using a Matrix Element Method and \textit{in Situ} Jet Energy Calibration
Title | Top Quark Mass Measurement in the Lepton + Jets Channel Using a Matrix Element Method and \textit{in Situ} Jet Energy Calibration PDF eBook |
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Pages | 7 |
Release | 2010 |
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A precision measurement of the top quark mass m{sub t} is obtained using a sample of t{bar t} events from p{bar p} collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m{sub t} and a parameter [Delta]{sub JES} used to calibrate the jet energy scale in situ. Using a total of 1087 events, a value of m{sub t} = 173.0 ± 1.2 GeV/c2 is measured.
Top Quark Mass Measurement in the Lepton Plus Jets Channel Using a Modified Matrix Element Method
Title | Top Quark Mass Measurement in the Lepton Plus Jets Channel Using a Modified Matrix Element Method PDF eBook |
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Pages | 46 |
Release | 2008 |
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The authors report a measurement of the top quark mass, m{sub t}, obtained from p{bar p} collisions at (square root)s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. They analyze a sample corresponding to an integrated luminosity of 1.9 rfb−1. They select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. They calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. The event likelihood is a function of m{sub t} and a parameter JES that determines in situ the calibration of the jet energies. They use a neural network discriminant to distinguish signal from background events. They also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, they find m{sub t} = 172.7 ± 1.8 (stat. + JES) ± 1.2(syst.) GeV/c2.
Precision Measurement of the Top Quark Mass in the Lepton + Jets Channel Using a Matrix Element Method with Quasi-Monte Carlo Integration
Title | Precision Measurement of the Top Quark Mass in the Lepton + Jets Channel Using a Matrix Element Method with Quasi-Monte Carlo Integration PDF eBook |
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Pages | 177 |
Release | 2009 |
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This thesis presents a measurement of the top quark mass obtained from p{bar p} collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. The measurement uses a matrix element integration method to calculate a t{bar t} likelihood, employing a Quasi-Monte Carlo integration, which enables us to take into account effects due to finite detector angular resolution and quark mass effects. We calculate a t{bar t} likelihood as a 2-D function of the top pole mass m{sub t} and [Delta]{sub JES}, where [Delta]{sub JES} parameterizes the uncertainty in our knowledge of the jet energy scale; it is a shift applied to all jet energies in units of the jet-dependent systematic error. By introducing [Delta]{sub JES} into the likelihood, we can use the information contained in W boson decays to constrain [Delta]{sub JES} and reduce error due to this uncertainty. We use a neural network discriminant to identify events likely to be background, and apply a cut on the peak value of individual event likelihoods to reduce the effect of badly reconstructed events. This measurement uses a total of 4.3 fb−1 of integrated luminosity, requiring events with a lepton, large E{sub T}, and exactly four high-energy jets in the pseudorapidity range.
Measurement of the Top Quark Mass with a Matrix Element Method in the Lepton Plus Jets Channel at CDF.
Title | Measurement of the Top Quark Mass with a Matrix Element Method in the Lepton Plus Jets Channel at CDF. PDF eBook |
Author | Brian Mohr |
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Pages | 5 |
Release | 2006 |
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The authors present a measurement of the mass of the top quark from p{bar p} collisions at 1.96 TeV observed with the Collider Detector at Fermilab (CDF) at the Fermilab Tevatron Run II. The events have the decay signature of p{bar p} {yields} t{bar t} in the lepton plus jets channel in which at least one jet is identified as coming from a secondary vertex and therefore a b-hadron. The largest systematic uncertainty, the jet energy scale (JES), is convoluted with the statistical error using an in-situ measurement of the hadronic W boson mass. They calculate a likelihood for each event using leading-order t{bar t} and W+jets cross-sections and parameterized parton showering. The final measured top quark mass and JES systematic is extracted from a joint likelihood of the product of individual event likelihoods. From 118 events observed in 680 pb{sup -1} of data, they measure a top quark mass of 174.09 {+-} 2.54 (stat+JES) {+-} 1.35(syst) GeV/c{sup 2}.
Top Quark Physics at Hadron Colliders
Title | Top Quark Physics at Hadron Colliders PDF eBook |
Author | Arnulf Quadt |
Publisher | Springer Science & Business Media |
Pages | 166 |
Release | 2007-08-16 |
Genre | Science |
ISBN | 3540710604 |
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.
A Measurement of the Top Quark Mass with a Matrix Element Method
Title | A Measurement of the Top Quark Mass with a Matrix Element Method PDF eBook |
Author | Adam Paul Gibson |
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Pages | 400 |
Release | 2006 |
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