Download or read book Top Quark Properties Studies at the Tevatron written by and published by . This book was released on 2013 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of Top Quark Properties at the Tevatron written by and published by . This book was released on 2012 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the recent measurements of the top quark properties in proton antiproton collisions at √s = 1.96 TeV is presented. These measurements are based on 5.4-8.7 fb−1 of data collected with the D0 and CDF experiments at the Fermilab Tevatron collider. The top quark mass and width measurements, studies of the spin correlation in top quark pair production, W boson helicity measurement, searches for anomalous top quark couplings and Lorentz invariance violation are discussed.

Download or read book Top Quark Properties written by and published by . This book was released on 2011 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its discovery in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron collider, the top quark has undergone intensive studies. Besides the Tevatron experiments, with the start of the LHC in 2010 a top quark factory started its operation. It is now possible to measure top quark properties simultaneously at four different experiments, namely ATLAS and CMS at LHC and CDF and D0 at Tevatron. Having collected thousands of top quarks each, several top quark properties have been measured precisely, while others are being measured for the first time. In this article, recent measurements of top quark properties from ATLAS, CDF, CMS and D0 are presented, using up to 5.4 fb−1 of integrated luminosity at the Tevatron and 1.1 fb−1 at the LHC. In particular, measurements of the top quark mass, mass difference, foward backward charge asymmetry, t{bar t} spin correlations, the ratio of branching fractions, W helicity, anomalous couplings, color flow and the search for flavor changing neutral currents are discussed.

Download or read book Studies of Top Quark Properties and Search for Electroweak Single Top Quark Production at the Tevatron written by and published by . This book was released on 2007 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark was discovered in 1995 by the CDF and D0 experiments at the Fermilab Tevatron during the Run I operation. Since the start of the Tevatron Run II in 2001, both experiments have collected (almost equal to)2 fb−1 data samples, which are over twenty times larger than that used in the Run 1 discovery. This larger data sample allows more precise studies of top-quark properties; differences between observed top-quark properties and the Standard Model (SM) prediction may give hints to possible physics beyond the SM. Here we present the latest results on the measurements of top-quark properties and the search for electroweak (EW) single top quark production from the CDF and D0 collaborations. The integrated luminosity used for the measurements corresponds to about 1 fb−1.

Download or read book Top Quark Properties from the Tevatron written by Markus Klute and published by . This book was released on 2006 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes latest measurements and studies of top quark properties from the Tevatron in Run II with an integrated luminosity of up to 750 pb{sup -1}. Due to its large mass of about 172 GeV/c{sup 2}, the top quark provides a unique environment for tests of the Standard Model and is believed to yield sensitivity to new physics beyond the Standard Model. With data samples of close to 1 fb{sup -1} the CDF and D0 collaborations at the Tevatron enter a new area of precision top quark measurements.

Download or read book Top Quark Properties at the TeVatron written by and published by . This book was released on 2011 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discovered in 1995 by CDF and D0 at the Fermilab Tevatron collider, the top quark remains interesting to test the Standard Model. Having collected more than 7 fb−1 of integrated luminosity with both experiments until today, several top quark properties have been measured with increasing precision, while other properties have been investigated for the first time. In this article recent measurements of top quark properties from CDF and D0 are presented, using between 1 fb−1 and 4.8 fb−1 of data. In particular, the measurement of the top quark mass, the top quark width, the top antitop mass difference, a check of the electric charge of the top quark, measurements of the top antitop quark spin correlation and W helicity as well as a search for charged Higgs bosons are discussed.

Download or read book Measurements of Top Quark Properties at the Tevatron written by and published by . This book was released on 2012 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark is the most recently discovered of the standard model quarks, and studies of its properties are important tests of the standard model. Many measurements of top properties have been produced by the CDF and D0 collaborations, which study top quarks produced in p{bar p} collisions at the Fermilab Tevatron with a center-of-mass energy √s = 1.96 TeV. We describe recent results from top properties measurements at the Tevatron using datasets corresponding to integrated luminosities up to 8.7 fb−1.

Download or read book Measurements of Top Quark Properties at the Tevatron Collider written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The discovery of the top quark in 1995 opened a whole new sector of investigation of the Standard Model; today top quark physics remains a key priority of the Tevatron program. Some of the measurements of top quark properties, for example its mass, will be a long-standing legacy. The recent evidence of an anomalously large charge asymmetry in top quark events suggests that new physics could couple preferably with top quarks. I will summarize this long chapter of particle physics history and discuss the road the top quark is highlighting for the LHC program.

Download or read book Properties of the Top Quark written by and published by . This book was released on 2009 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of particle physics is the understanding of elementary particles and their interactions. The current theory of elementary particle physics, the Standard Model, contains twelve different types of fermions which (neglecting gravity) interact through the gauge bosons of three forces. In addition a scalar particle, the Higgs boson, is needed for theoretical consistency. These few building blocks explain all experimental results found in the context of particle physics, so far. Nevertheless, it is believed that the Standard Model is only an approximation to a more complete theory. First of all the fourth known force, gravity, has withstood all attempts to be included until now. Furthermore, the Standard Model describes several features of the elementary particles like the existence of three families of fermions or the quantisation of charges, but does not explain these properties from underlying principles. Finally, the lightness of the Higgs boson needed to explain the symmetry breaking is difficult to maintain in the presence of expected corrections from gravity at high scales. This is the so called hierarchy problem. In addition astrophysical results indicate that the universe consists only to a very small fraction of matter described by the Standard Model. Large fractions of dark energy and dark matter are needed to describe the observations. Both do not have any correspondence in the Standard Model. Also the very small asymmetry between matter and anti-matter that results in the observed universe built of matter (and not of anti-matter) cannot be explained until now. It is thus an important task of experimental particle physics to test the predictions of the Standard Model to the best possible accuracy and to search for deviations pointing to necessary extensions or modifications of our current theoretical understanding. The top quark was predicted to exist by the Standard Model as the partner of the bottom quark. It was first observed in 1995 by the Tevatron experiments CDF and D0 and was the last of the quarks to be discovered. As the partner of the bottom quark the top quark is expected to have quantum numbers identical to that of the other known up-type quarks. Only the mass is a free parameter. We now know that it is more than 30 times heavier than the next heaviest quark, the bottom quark. Thus, within the Standard Model all production and decay properties are fully defined. Having the complete set of quarks further allows to verify constraints that the Standard Model puts on the sum of all quarks or particles. This alone is reason enough to experimentally study the top quark properties. The high value of the top quark mass and its closeness to the electroweak scale has inspired people to speculate that the top quark could have a special role in the electroweak symmetry breaking. Confirming the expected properties of the top quark experimentally establishes the top quark as we expect it to be. Any deviation from the expectations gives hints to new physics that may help to solve the outstanding questions. In this review the recent results on top quark properties obtained by the Tevatron experiments CDF and D0 are summarized. At the advent of the LHC special emphasis is given to the basic measurement methods and the dominating systematic uncertainties. After a short introduction to the Standard Model and the experimental environment in the remainder of this chapter, Chapter 2 describes the current status of top quark mass measurements. Then measurments of interaction properties are described in Chapter 3. Finally, Chapter 4 deals with analyses that consider hypothetical particles beyond the Standard Model in the observed events.

Download or read book Recent Results on the Top Quark from the Tevatron Collider Experiments written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents the latest measurements of the properties of the top quark as determined by the DØ and CDF collaborations at the Fermilab Tevatron p{anti p} Collider. Both experiments have studied the all-hadronic decay mode of t{anti t} events. The top quark mass measurement has been refined over the past year, with the addition of new channels and a re-evaluation of some of the earlier ones. There are recent studies of the mass of the t{anti t} system, the helicity of the W bosons in the top quark decays, and of the correlation of the spins of the top and antitop quarks. New results are also reported on searches for charged Higgs bosons in top quark decay, and for electroweak production of single top quarks.

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 Top Properties and Rare Decays from the Tevatron written by Arnulf Quadt and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark is the most recently discovered quark. Relatively little is known about its properties so far. Due to its very large mass of about 175 GeV/c{sup 2}, the top quark behaves differently from all other quarks and provides a unique environment for tests of the Standard Model. Furthermore, it is believed to yield sensitivity to physics beyond the Standard Model. This report discusses the latest measurements and studies of top quark properties and rare decays from the Tevatron in Run II.

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 Studies of Top Quark Properties at the D0 Experiment written by and published by . This book was released on 2010 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present an overview of selected top quark properties in lepton + jets and dilepton final states based on 1-4.3 fb−1 of data, collected with the D0 experiment at the Fermilab Tevatron collider. The recent measurement of theW boson helicity, a search for anomalous top quark couplings, and measurements of spin correlations and forward backward color charge asymmetry are discussed. Since the discovery of top quark in 1995 by CDF and D0, the discovered particle is considered as a standard model (SM) top quark, mainly because its cross-section is in a reasonable agreement with QCD calculations and its measured mass is in a agreement with indirect top quark mass determinations. However the limited precision of these comparisons doesn't exclude the possibility of non SM contributions in the top quark final states, so direct measurements of top quark properties are useful to confirm its SM nature. In this article we report several recent measurements done using 1-4.3 fb−1 of data collected with the D0 detector at the Fermilab Tevatron collider.

Download or read book Top Quark Properties at the Tevatron written by Aran Garcia-Bellido and published by . This book was released on 2004 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent preliminary results on top quark properties from the CDF and D0 collaborations at the Fermilab Tevatron are described. These analyses include: measurements of the ratio B(t {yields} Wb)/B(t {yields} Wq) and of B(t {yields} {tau}vq), search for anomalous kinematics, studies on the helicity of W bosons originating from top quark decays, spin correlations between top quark pairs, and searches for t{bar t} resonance production in models beyond the standard model.

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 at the New Physics Frontier written by Efe Yazgan and published by . This book was released on 2024-03-21 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hunt for top quarks began back in the 1970s after the proposal of the sixquark model by Kobayashi and Maskawa, and it was discovered in 1995 at the Fermilab Tevatron. It was experimentally established by five different experiments in different production modes and a variety of collision energies. At the CERN Large Hadron Collider (LHC), top quark-antiquark pairs are routinely produced at a rate of about six per minute, enabling experiments to make detailed measurements of the properties of top quarks. The analysis of the data collected at the Tevatron and the LHC experiments has revealed, so far, good agreement with the standard model (SM) predictions. The top quark is the most massive elementary particle identified to date: not only does it have a privileged Yukawa coupling to the Higgs boson, but its mass is also significantly higher than that of the Higgs boson. Owing to its large mass, the top quark decays before hadronization, making the study of "bare" quark properties possible in experimental settings. Therefore, top quark physics simultaneously pushes the frontiers of quantum chromodynamics, electroweak, and flavor physics. The aim of this reprint is to provide a comprehensive review of the status and prospects of top quark physics at the LHC and possible future colliders. We have included articles that especially emphasize where the present understanding is incomplete and suggest new directions for research in this area.