Twelve years after the discovery of the top quark at Fermilab's Tevatron, they are now finally beginning to shed light on this peculiarily massive quark. With 1-1.7 fb−1 of integrated luminosity collected by the CDF detector, they are able to probe the knowledge of the top quark physics, and to search for signals of physics beyond the Standard Model. In this paper, they present results of measurements of top quark properties, as well as tests for the production mechanism of the top quark. They also describe CDF latest searches for beyond Standard Model couplings of the top quark. Finally, they present the most recent searches for direct production of new particles in the collected data samples.
The Evidence for the Top Quark offers both a historical and philosophical perspective on an important recent discovery in particle physics: the first evidence for the elementary particle known as the top quark. Drawing on published reports, oral histories, and internal documents from the large collaboration that performed the experiment, Kent Staley explores in detail the controversies and politics that surrounded this major scientific result.At the same time the book seeks to defend an objective theory of scientific evidence based on error probabilities.
The current status of the Top quark search at CDF is presented. A lower limit on the Top mass of 113 GeV has been established using the dilepton channel with the data collected during the 1988--1989 and 1992--1993 runs at (square root)s= 1.8 TeV. Prospects for Top quark discovery during the 1993--1994 run are also outlined.
Searches for the top quark in p{bar p} collisions at (square root)s = 1.8 TeV are described. The analyses are based on data with an integrated luminosity of 4.4 pb−1 recorded with the Collider Detector at Fermilab in the 1988--1989 run. An upper limit on the t{bar t} cross section is obtained. The top quark with mass below 89 GeV/c2 is excluded at the 95% CL. Prospects for searches for the top quark in the future are presented. We also briefly present results on searches for supersymmetric particles. 14 refs., 10 figs.
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.
The top quark is most often produced in t$\bar{t}$ pairs via the strong interaction, however, electroweak production of a single top quark is also possible. Electroweak or 'single-top' quark production is more difficult to observe than t$\bar{t}$ production. A measurement of single-top quark production can provide an interesting test of the Standard Model as well as a measurement of the CKM matrix element Vtb. This thesis describes a measurement of single-top quark production in pp collisions at √s=1.96 TeV usign the CDF II detector at the Fermilab Tevatron. This search is performed using a Multivariate Likelihood technique with 2.2 fb-1 of data.
During the 1988--89 Tevatron Collider run the CDF detector has collected data for an integrated luminosity of 4.4 pb−1. The sample has been used to search for the top quark in several topologies. Preliminary results show that a top mass below 89 GeV is excluded at the 95% confidence level, thus extending the limit of 77 GeV previously published by CDF. 14 refs., 8 figs.
The top quark with its mass of about 172 GeV/c{sup 2} is the most massive fundamental particle observed by experiment. In this talk they highlight the most recent measurements of several top quark properties performed with the CDF detector based on data samples corresponding to integrated luminosities up to 1 fb{sup -1}. These results include a search for top quark pair production via new massive resonances, measurements of the helicity of the W boson from top-quark decay, and a direct limit on the lifetime of the top quark.
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.
