Download or read book Measurement of Single Top Production at the Tevatron written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This article reports on first evidence for single top-quark production by the CDF and D0 collaboration at the Tevatron. Both experiments have measured the cross section with more the 3 standard deviations significance using a data set that corresponds to an integrated luminosity of 2.2 fb−1 and 0.9 fb−1, respectively. Also direct measurements of the CKM matrix element.
Download or read book Evidence for Single Top Production at the Tevatron written by and published by . This book was released on 2008 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present first evidence for the production of single top quarks at the Fermilab Tevatron p{bar p} collider. Both D0 and CDF experiments have measured the single top production cross section with a 3-standard-deviation significance using 0.9 fb−1 and 2.2 fb−1 of lepton+jets data, respectively. A direct measurement of the CKM matrix element that describes the Wtb coupling is also performed for the first time.
Download or read book Single Top Production and Top Properties at the Tevatron written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We summarize recent measurements made at the Tevatron Collider using top event candidates. Cross section and mass measurements are discussed in a separate contribution to these Proceedings. Here we report on studies of the top PT distribution in t{anti t} production and studies of single top production. Properties of top decays examined are: BF(t --> Wb)/BF(t --> Wq), helicity amplitudes of W's from top decays and correlations of t{anti t} decay products. Searches for new physics in rare top decays and a search for a state X --> t{anti t} are also reported.
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 Adams After Noon Press Clippings written by and published by . This book was released on 19?? with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Single Top Quark Production at the Tevatron written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The observation of single top quark production by the CDF and D0 collaborations is one of the flagship measurements of the Run II of the Tevatron. The Tevatron combined single top quark cross section is measured to be: [sigma](tb + X, tqb + X) = 2.8{sub -0.5}{sup +0.6} pb for a top quark mass of 170 GeV. This result is in agreement with the standard model production of a single top quark together with a jet in p{bar p} collisions at √s = 1.96 TeV and allows to measure the CKM matrix element.
Download or read book Discovery of Single Top Quark Production written by Dag Gillberg and published by Springer Science & Business Media. This book was released on 2011-01-22 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark is by far the heaviest known fundamental particle with a mass nearing that of a gold atom. Because of this strikingly high mass, the top quark has several unique properties and might play an important role in electroweak symmetry breaking—the mechanism that gives all elementary particles mass. Creating top quarks requires access to very high energy collisions, and at present only the Tevatron collider at Fermilab is capable of reaching these energies. Until now, top quarks have only been observed produced in pairs via the strong interaction. At hadron colliders, it should also be possible to produce single top quarks via the electroweak interaction. Studies of single top quark production provide opportunities to measure the top quark spin, how top quarks mix with other quarks, and to look for new physics beyond the standard model. Because of these interesting properties, scientists have been looking for single top quarks for more than 15 years. This thesis presents the first discovery of single top quark production. It documents one of the flagship measurements of the D0 experiment, a collaboration of more than 600 physicists from around the world. It describes first observation of a physical process known as “single top quark production”, which had been sought for more than 10 years before its eventual discovery in 2009. Further, his thesis describes, in detail, the innovative approach Dr. Gillberg took to this analysis. Through the use of Boosted Decision Trees, a machine-learning technique, he observed the tiny single top signal within an otherwise overwhelming background. This Doctoral Thesis has been accepted by Simon Fraser University, Burnaby, BC, Canada.
Download or read book Observation of S Channel Single Top Quark Production at the Tevatron written by and published by . This book was released on 2014 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Testing the Standard Model (SM) and looking for new phenomena have been the focus of generations of particle physicists in the last decades. Following this spirit, this thesis presents two searches. The first is the search for single top quark production from the exchange of an s-channel virtual W boson using events with an imbalance in the total transverse energy, b-tagged jets, and no identified leptons. Assuming the electroweak production of top quarks of mass 172.5 GeV/c2 in the s-channel, a cross section of 1.12+0.61 -0.57 (stat+syst) pb, with a significance of 1.9 standard deviations, is measured. This measurement is combined with the result obtained from events with an imbalance in total transverse momentum, b-tagged jets, and exactly one identified lepton, yielding a cross section of 1.36+0.37 -0.322 (stat+syst) pb, with a significance of 4.2 standard deviations. The first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements is also reported. The measured cross section is [sigma]s = 1.29+0.26 -0.244 pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is 1.8 10-10, corresponding to a significance of 6.3 standard deviation. The second is the search for W'-like resonances decaying to tb. No significant excess above the SM prediction is found. Using a benchmark W' → tb left-right symmetric model, 95% C.L. mass-dependent upper limits are placed on the W0 boson production cross section times branching ratio to tb. Assuming a W' boson with SM-like couplings and allowed (forbidden) decay to leptons, W' → tb is excluded with 95% C.L. for W' boson masses below 860 (880) GeV/c2. Relaxing the hypothesis on SM-like couplings, we exclude W' boson coupling strength values as a function of the W' boson mass above 10% of the SM coupling strength for MW' = 300 GeV/c2. The constraints obtained with the present analysis are the most stringent for charged resonance masses below 570 GeV/c2 decaying to a top and a bottom quark.
Download or read book Tevatron Combination of Single Top Quark Production and Vtb Measurement written by and published by . This book was released on 2010 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: After the first observation of the inclusive single top-quark production in the s- and t-channels by CDF and D0, both Tevatron collaborations combined their measurements using the distributions of their multivariate discriminants. A Bayesian analysis is used to extract the cross section at a center of mass energy of 1.96 TeV from 3.2 fb−1 (CDF) and 2.3 fb−1 (D0) of data, respectively. For a top quark mass of 170 GeV/c2, a cross section of 2.76 + 0.58 - 0.47 pb is extracted while the CKM matrix element.
Download or read book Observation of S channel Production of Single Top Quarks at the Tevatron written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb-1 per experiment. The measured cross section is $\sigma_s = 1.29^{+0.26}_{-0.24}$ pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is $1.8 \times 10^{-10}$, corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks.
Download or read book Measurements of Top Quark Production and Properties at the Tevatron written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this letter, we summarize the latest results of the top-quark production and properties at the Tevatron. We do not include results of the top-quark mass and single top-quark production as they were presented in separate talks. The results of the measurements are mostly consistent with the standard-model predictions. However, by looking at the production asymmetry measured by CDF, one can see a discrepancy in both, $t\bar{t}$ inclusive and lepton-based measurements. D\O\ results of production asymmetry are compatible with the standard-model predictions as well as with the CDF results.
Download or read book Single Top Production at the Tevatron written by and published by . This book was released on 2012 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present recent results of single top quark production in the lepton plus jet final state, performed by the CDF and D0 collaborations based on 7.5 and 5.4 fb−1 of p{bar p} collision data collected at √s = 1.96 TeV from the Fermilab Tevatron collider. Multivariate techniques are used to separate the single top signal from the backgrounds. Both collaborations present measurements of the single top quark cross section and the CKM matrix element.
Download or read book Summary of Single Top Quark Production at the Tevatron written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of single-top quarks occurs via the weak interaction at the Fermilab Tevatron proton-antiproton collider. Single top quark events are selected in the lepton+jets final state by CDF and D0 and in the missing transverse energy plus jets final state by CDF. Multivariate classifiers separate the s-channel and t-channel single-top signals from the large backgrounds. The combination of CDF and D0 results leads to the first observation of the s-channel mode of single top quark production. The t-channel and single top combined cross sections have also been measured.
Download or read book Single Top Quark Measurements at the Tevatron written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper reports the most recent measurements of single top quark production performed by CDF and D0 collaborations in proton-antiproton collisions at Tevatron. Events are selected in the lepton+jets final state by CDF and D0 and in the missing transverse energy plus jets final state by CDF. The small single top signal in s-channel, t-channel and inclusive s+t channel is separated from the large background by using different multivariate techniques. We also present the most recent results on extraction of the CKM matrix element $
Download or read book Single Top Quarks at the Tevatron written by and published by . This book was released on 2008 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: After many years searching for electroweak production of top quarks, the Tevatron collider experiments have now moved from obtaining first evidence for single top quark production to an impressive array of measurements that test the standard model in several directions. This paper describes measurements of the single top quark cross sections, limits set on the CKM matrix element.
Download or read book Top Quark Pair Production written by Anna Christine Henrichs and published by Springer Science & Business Media. This book was released on 2013-10-04 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: Before any kind of new physics discovery could be made at the LHC, a precise understanding and measurement of the Standard Model of particle physics' processes was necessary. The book provides an introduction to top quark production in the context of the Standard Model and presents two such precise measurements of the production of top quark pairs in proton-proton collisions at a center-of-mass energy of 7 TeV that were observed with the ATLAS Experiment at the LHC. The presented measurements focus on events with one charged lepton, missing transverse energy and jets. Using novel and advanced analysis techniques as well as a good understanding of the detector, they constitute the most precise measurements of the quantity at that time.
Download or read book Particle Theory And Phenomenology Proceedings Of Xvii International Kazimierz Meeting On Particle Physics And Of The Madison Phenomenology Symposium written by Kenneth E Lassila and published by World Scientific. This book was released on 1996-11-30 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, leading researchers in theoretical and experimental particle physics summarize the recent developments in their areas of expertise. There are also concentrated presentations on top quark discoveries and new theory consequences of top data.
