Single Top at the Tevatron

Single Top at the Tevatron PDF Author: Anyes Taffard
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Book Description
The authors review the status of the search for the electroweak production of single top quarks by the CDF and D0 collaborations at the Fermilab Tevatron proton-antiproton collider using Run II data. With a dataset of approximately 160 pb{sup -1} for CDF and 230 pb{sup -1} for D0, neither experiment finds evidence for single top production and sets 95% C.L. upper limits on the production cross-sections. The CDF limits are 10.1 pb for the t channel, 13.6 pb for the s channel and 17.8 pb for the combined production cross-sections of s and t channel. The D0 limits are 5.0 pb for the t channel, 6.4 pb for the s-channel production cross-sections. Both experiments investigate the prospect for a 3{sigma} evidence and a 5{sigma} discovery.

Single Top at the Tevatron

Single Top at the Tevatron PDF Author: Anyes Taffard
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Book Description
The authors review the status of the search for the electroweak production of single top quarks by the CDF and D0 collaborations at the Fermilab Tevatron proton-antiproton collider using Run II data. With a dataset of approximately 160 pb{sup -1} for CDF and 230 pb{sup -1} for D0, neither experiment finds evidence for single top production and sets 95% C.L. upper limits on the production cross-sections. The CDF limits are 10.1 pb for the t channel, 13.6 pb for the s channel and 17.8 pb for the combined production cross-sections of s and t channel. The D0 limits are 5.0 pb for the t channel, 6.4 pb for the s-channel production cross-sections. Both experiments investigate the prospect for a 3{sigma} evidence and a 5{sigma} discovery.

Top Quark Physics at Hadron Colliders

Top Quark Physics at Hadron Colliders PDF Author: Arnulf Quadt
Publisher: Springer Science & Business Media
ISBN: 3540710604
Category : Science
Languages : en
Pages : 166

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Book Description
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.

Discovery of Single Top Quark Production

Discovery of Single Top Quark Production PDF Author: Dag Gillberg
Publisher: Springer Science & Business Media
ISBN: 1441977996
Category : Science
Languages : en
Pages : 149

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Book Description
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.

Evidence for Single Top Production at the Tevatron

Evidence for Single Top Production at the Tevatron PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Book Description
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.

Higher Order QCD Corrections to Single Top Quark Production

Higher Order QCD Corrections to Single Top Quark Production PDF Author: Mohammad Assadsolimani
Publisher: disserta Verlag
ISBN: 3954256746
Category : Science
Languages : en
Pages : 161

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Book Description
It is known that the LHC has a considerable discovery potential because of its large centre-of-mass energy (vs =14 TeV) and the high design luminosity. In addition, the two experiments ATLAS and CMS perform precision measurements for numerous models in physics. The increasing experimental precision demands an even higher level of accuracy on the theoretical side. For a more precise prediction of outcomes, one has to consider the corrections obtained typically from Quantum Chromodynamics (QCD). The calculation of these corrections in the high energy regime is described by perturbation theory. In the present study, multi-loop calculations in QCD, including in particular two-loop corrections for single top quark production, are considered. There are several phenomenological motivations to study single top quark production: Firstly, the process is sensitive to the electroweak Wtb-vertex; moreover, non-standard couplings can hint at physics beyond the Standard Model. Secondly, the t-channel cross section measurement provides information on the b-quark Parton Distribution Functions (PDF). Finally, single top quark production enables us to directly measure the Cabibbo-Kobayashi-Maskawa(CKM) matrix element Vtb. The next-to-next-to-leading-order (NNLO) calculation of the single top quark production has many building blocks. In this study, two blocks will be presented: one-loop corrections squared and two-loop corrections interfered with Born. Initially, the one-loop squared contribution at NNLO for single top quark production will be calculated. Before we begin with the calculation of the two-loop corrections to single top quark production, we calculate the QCD form factors of heavy quarks at NNLO, along with the axial vector coupling as a first independent check. A comparison with the relevant literature suggests that this approach is in line with generally accepted procedure. This consistency check provides a proof of the validity of our setup. In the next step, the two-loop corrections to single top quark production will be calculated. After reducing all occurring tensor integrals to scalar integrals, we apply the integration by parts method (IBP) to find the master integrals. This step is a major challenge compared to all similar calculations because of the number of variables in the problem (two Mandelstam variables s and t, the dimension d and the mass of the top quark mt as well as the mass of the W boson mw). Finally, the calculation of the three kinds of topologies – vertex corrections, double boxes and non-planar double boxes – in the two-loop contribution at NNLO calculation will be presented.

\Ttbar and Single Top Cross Sections at the Tevatron

\Ttbar and Single Top Cross Sections at the Tevatron PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Book Description
We present a summary of the latest measurements of the top pair and single top cross sections performed by the CDF and D0 collaborations at the Fermilab Tevatron collider. The Fermilab Tevatron collider ended its run on September 30, 2011 after delivering more than 10 fb−1 of p{bar p} collision data per experiment at √s = 1.96 TeV. A large sample of top quarks collected by the CDF and D0 experiments allows to perform precision measurements of their production which is predicted to occur within the standard model (SM) either in pairs via strong interactions or as single top events via electroweak interactions. Such measurements represent an important test of the theoretical calculations which predict the t{bar t} and single top production cross sections with a precision of 6% to 8% and 5%, respectively. Precise measurements of top pair cross section (?{sub t{bar t}}) in different t{bar t} final states and single top production via different production mechanisms are highly desirable as they are sensitive to the non-SM particles that may appear in top quark production or decays.

Uncovering the Single Top

Uncovering the Single Top PDF Author: Jorge Armando Benitez
Publisher:
ISBN:
Category : Electroweak interactions
Languages : en
Pages : 724

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Book Description


Summary of Single Top Quark Production at the Tevatron

Summary of Single Top Quark Production at the Tevatron PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
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.

Single Top Production at the Tevatron

Single Top Production at the Tevatron PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Book Description
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.

Measurement of Single Top Production at the Tevatron

Measurement of Single Top Production at the Tevatron PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
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.