Download or read book Measurement of the Top Quark Mass in the Dilepton Channel at CDF and written by Tuula Maki and published by . This book was released on 2005 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present recent analyses of the top quark mass measurement in dileptonic channel. The measurements use 200-360 pb{sup -1} of data collected by CDF and D0 experiments. The future prospects are discussed as well.

Download or read book Measurement of the Top Quark Mass in the t bar t Dilepton Channel Using the Full CDF Run II Data Set written by and published by . This book was released on 2015 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Measurement of the Top Quark Mass in the Dilepton Decay Channel at CDF II written by Bodhitha Anjalike Jayatilaka and published by . This book was released on 2006 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Precision Measurement of the Top Quark Mass from Dilepton Events at CDF II written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The First Measurement of the Top Quark Mass at CDF II in the Lepton jets and Dilepton Channels Simultaneously written by and published by . This book was released on 2008 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9 fb−1 of p{bar p} collisions collected at (square root)s = 1.96 TeV with the CDF II detector at Fermilab's Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton + jets and dilepton decay channels simultaneously. They reconstruct two observables in each channel and use a non-parametric kernel density estimation technique to derive two-dimensional probability density functions from simulated signal and background samples. The observables are the top quark mass and the invariant mass of two jets from the W decay in the lepton + jets channel, and the top quark mass and the scalar sum of transverse energy of the event in the diletpon channel. They perform a simultaneous fit for the top quark mass and the jet energy scale, which is constrained in situ by the hadronic W boson mass. using 332 lepton + jets candidate events and 144 diletpon candidate events, they measure the top quark mass to be m{sub top} = 171.9 ± 1.7 (stat. + JES) ± 1.1 (other sys.) GeV/c2 = 171.9 ± 2.0 GeV/c2.

Download or read book Precision Measurement of Top Quark Mass in Dilepton Channel written by Bodhitha Jayatilaka and published by . This book was released on 2006 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present recent measurements of the top quark mass using events collected at the CDF and D0 detectors from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron. These analyses are performed using events consistent with the decay channel t{bar t} {yields} {bar b}{ell}{sup -}{bar v}{sub {ell}}b{ell}' + v'{sub {ell}}, or the dilepton channel. 230-360 pb{sup -1} of data are used.

Download or read book Measurement of the Top Quark Mass in the Dilepton Channel Using the Neutrino Weighting Algorithm at CDF II written by Simon Sabik and published by . This book was released on 2006 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: We measure the top quark mass using approximately 359 pb-1 of data from pp− collisions at s = 1.96 GeV at CDF Run II. We select tt− candidates that are consistent with two W bosons decaying to a charged lepton and a neutrino following tt− & rarr; W+W-bb− & rarr; l+l- nn & d1; bb−. Only one of the two charged leptons is required to be identified as an electron or a muon candidate, while the other is simply a well measured track. We use a neutrino weighting algorithm which weighs each possibility of neutrino direction to reconstruct a top quark mass in each event. We compare the resulting distribution to Monte Carlo templates to obtain a top quark mass of 170.8+6.9-6.5 (stat) +/- 4.6 (syst) GeV/c 2.

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 Simultaneously in Dilepton and Lepton Jets Decay Channels written by and published by . This book was released on 2008 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present the first measurement of the top quark mass using simultaneously data from two decay channels. They use a data sample of (square root)s = 1.96 TeV collisions with integrated luminosity of 1.9 fb−1 collected by the CDF II detector. They select dilepton and lepton + jets channel decays of t{bar t} pairs and reconstruct two observables in each topology. They use non-parametric techniques to derive probability density functions from simulated signal and background samples. The observables are the reconstructed top quark mass and the scalar sum of transverse energy of the event in the dilepton topology and the reconstructed top quark mass and the invariant mass of jets from the W boson decay in lepton + jets channel. They perform a simultaneous fit for the top quark mass and the jet energy scale which is constrained in situ by the hadronic W boson resonance from the lepton + jets channel. Using 144 dilepton candidate events and 332 lepton + jets candidate events they measure: M{sub top} = 171.9 ± 1.7 (stat. + JES) ± 1.1 (other sys.) GeV/c2 = 171.9 ± 2.0 GeV/c2. The measurement features a robust treatment of the systematic uncertainties, correlated between the two channels and develops techniques for a future top quark mass measurement simultaneously in all decay channels. Measurements of the W boson mass and the top quark mass provide a constraint on the mass of the yet unobserved Higgs boson. The Higgs boson mass implied by measurement presented here is higher than Higgs boson mass implied by previously published, most precise CDF measurements of the top quark mass in lepton + jets and dilepton channels separately.

Download or read book Top Quark Mass Measurement from Dilepton Events at CDF II with the Matrix element Method written by and published by . This book was released on 2006 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Top Quark Mass in the Dilepton Final State Using the Matrix Element Method written by and published by . This book was released on 2008 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark, discovered in 1995 by the CDF and D0 experiments at the Fermilab Tevatron Collider, is the heaviest known fundamental particle. The precise knowledge of its mass yields important constraints on the mass of the yet-unobserved Higgs boson and allows to probe for physics beyond the Standard Model. The first measurement of the top quark mass in the dilepton channel with the Matrix Element method at the D0 experiment is presented. After a short description of the experimental environment and the reconstruction chain from hits in the detector to physical objects, a detailed review of the Matrix Element method is given. The Matrix Element method is based on the likelihood to observe a given event under the assumption of the quantity to be measured, e.g. the mass of the top quark. The method has undergone significant modifications and improvements compared to previous measurements in the lepton+jets channel: the two undetected neutrinos require a new reconstruction scheme for the four-momenta of the final state particles, the small event sample demands the modeling of additional jets in the signal likelihood, and a new likelihood is designed to account for the main source of background containing tauonic Z decay. The Matrix Element method is validated on Monte Carlo simulated events at the generator level. For the measurement, calibration curves are derived from events that are run through the full D0 detector simulation. The analysis makes use of the Run II data set recorded between April 2002 and May 2008 corresponding to an integrated luminosity of 2.8 fb−1. A total of 107 t{bar t} candidate events with one electron and one muon in the final state are selected. Applying the Matrix Element method to this data set, the top quark mass is measured to be m{sub top}{sup Run IIa} = 170.6 ± 6.1(stat.){sub -1.5}{sup +2.1}(syst.)GeV; m{sub top}{sup Run IIb} = 174.1 ± 4.4(stat.){sub -1.8}{sup +2.5}(syst.)GeV; m{sub top}{sup comb} = 172.9 ± 3.6(stat.) ± 2.3(syst.)GeV. Systematic uncertainties are discussed, and the results are interpreted within the Standard Model of particle physics. As the main systematic uncertainty on the top quark mass comes from the knowledge of the absolute jet energy scale, studies for a simultaneous measurement of the top quark mass and the b jet energy scale are presented. The prospects that such a simultaneous determination offer for future measurements of the top quark mass are outlined.

Download or read book Measurement of the Top Quark Mass in the Dilepton Final State Using the Matrix Element Method written by Alexander Grohsjean and published by Springer Science & Business Media. This book was released on 2010-10-01 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main pacemakers of scienti?c research are curiosity, ingenuity, and a pinch of persistence. Equipped with these characteristics a young researcher will be s- cessful in pushing scienti?c discoveries. And there is still a lot to discover and to understand. In the course of understanding the origin and structure of matter it is now known that all matter is made up of six types of quarks. Each of these carry a different mass. But neither are the particular mass values understood nor is it known why elementary particles carry mass at all. One could perhaps accept some small generic mass value for every quark, but nature has decided differently. Two quarks are extremely light, three more have a somewhat typical mass value, but one quark is extremely massive. It is the top quark, the heaviest quark and even the heaviest elementary particle that we know, carrying a mass as large as the mass of three iron nuclei. Even though there exists no explanation of why different particle types carry certain masses, the internal consistency of the currently best theory—the standard model of particle physics—yields a relation between the masses of the top quark, the so-called W boson, and the yet unobserved Higgs particle. Therefore, when one assumes validity of the model, it is even possible to take precise measurements of the top quark mass to predict the mass of the Higgs (and potentially other yet unobserved) particles.

Download or read book Top Quark Mass Measurement from Dilepton Events at CDF II written by and published by . This book was released on 2005 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combining the Top Quark Mass Results for Run 1 from CDF and D Zero written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: CDF and D0 have published or submitted for publication eleven papers [1-11] that include direct experimental measurements of the top quark mass. Each experiment has found that the lepton+jets channel [1,5,6,9,10,11,12] gives the most precise result. However, CDF and D0 have also measured the top quark mass in other decay topologies. Both D0 [2,6] and CDF [3,4] have published additional results in the dilepton channels, while CDF [8] has published a result in the all-hadronic channel. Our aim in this note is to reduce the overall uncertainty on the top quark mass measurement by combining the most recent and final of these measurements [1,2,3,7,8]. This note combines the mass from the five separate measurements taking into account the statistical and systematic uncertainties as well as the correlations in the systematic uncertainties. The final Tevatron top mass based on Run 1 data is m{sub t} = 174.3 " 3.2(stat) " 4.0(syst) GeV/c2. Combining the statistical and systematic uncertainties, the top mass is m{sub t} = 174.3 " 5.1 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 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 Measurement of the Top Quark Mass Using the Dilepton and Lepton Track Event Samples of the CDF Experiment on Tevatron In Russian written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: