A Measurement of the Top Pair Production Cross-section in the Dilepton Channel Using Lepton Plus Track Selection

A Measurement of the Top Pair Production Cross-section in the Dilepton Channel Using Lepton Plus Track Selection PDF Author: Corrinne Mills
Publisher: ProQuest
ISBN: 9780549152866
Category :
Languages : en
Pages : 388

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Book Description
Using 1.1 fb-1 of data collected by the Collider Detector at Fermilab (CDF) from Run II of the Fermilab Tevatron, we measure the tt production cross section in events with two leptons, significant missing transverse energy, and & ge;2 jets. As the Run II dataset grows, more stringent tests of Standard Model predictions for the top quark sector are becoming possible. The dilepton channel, where both top quarks decay t & rarr; Wb & rarr; & ell;nu b, is of particular interest due to its high purity even in the absence of a b jet "tagging" requirement. Use of an isolated track as the second lepton significantly increases the dilepton acceptance, at the price of some increase in background, particularly from W + jets events where one of the jets is identified as a lepton. With the amount of data available, it has been possible to improve the estimate of the contribution from that background, reflected in a reduced systematic uncertainty. Assuming a branching ratio of BR(W & rarr; & ell;nu) = 10.8% and a top mass of mt = 175 GeV/ c2, the measured cross-section is sigma(pp & rarr; tt) + 8.3 +/- 1.3(stat.) +/- 0.7(syst.) +/- 0.5(lumi.) pb. The result is consistent with the Standard Model prediction of 6.7+0.7-0.9 pb and represents a significant improvement in precision over previous results using this selection.

A Measurement of the Top Pair Production Cross-section in the Dilepton Channel Using Lepton Plus Track Selection

A Measurement of the Top Pair Production Cross-section in the Dilepton Channel Using Lepton Plus Track Selection PDF Author: Corrinne Mills
Publisher: ProQuest
ISBN: 9780549152866
Category :
Languages : en
Pages : 388

Get Book Here

Book Description
Using 1.1 fb-1 of data collected by the Collider Detector at Fermilab (CDF) from Run II of the Fermilab Tevatron, we measure the tt production cross section in events with two leptons, significant missing transverse energy, and & ge;2 jets. As the Run II dataset grows, more stringent tests of Standard Model predictions for the top quark sector are becoming possible. The dilepton channel, where both top quarks decay t & rarr; Wb & rarr; & ell;nu b, is of particular interest due to its high purity even in the absence of a b jet "tagging" requirement. Use of an isolated track as the second lepton significantly increases the dilepton acceptance, at the price of some increase in background, particularly from W + jets events where one of the jets is identified as a lepton. With the amount of data available, it has been possible to improve the estimate of the contribution from that background, reflected in a reduced systematic uncertainty. Assuming a branching ratio of BR(W & rarr; & ell;nu) = 10.8% and a top mass of mt = 175 GeV/ c2, the measured cross-section is sigma(pp & rarr; tt) + 8.3 +/- 1.3(stat.) +/- 0.7(syst.) +/- 0.5(lumi.) pb. The result is consistent with the Standard Model prediction of 6.7+0.7-0.9 pb and represents a significant improvement in precision over previous results using this selection.

A Measurement of the Top Pair Production Cross-section in the Dilepton Channel Using Lepton Plus Track Selection

A Measurement of the Top Pair Production Cross-section in the Dilepton Channel Using Lepton Plus Track Selection PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 214

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Book Description
Using 1.1 fb−1 of data collected by the Collider Detector at Fermilab (CDF) from Run II of the Fermilab Tevatron, they measure the t{bar t} production cross section in events with two leptons, significant missing transverse energy, and ≥ 2 jets. As the Run II dataset grows, more stringent tests of Standard Model predictions for the top quark sector are becoming possible. The dilepton channel, where both top quarks decay t → Wb → l[nu]b, is of particular interest due to its high purity even in the absence of a b jet 'tagging' requirement. Use of an isolated track as the second lepton significant increases the dilepton acceptance, at the price of some increase in background, particular from W + jets events where one of the jets is identified as a lepton. With the amount of data available, it has been possible to improve the estimate of the contribution from that background, reflected in a reduced systematic uncertainty. Assuming a branching ratio of BR(W → l[nu]) = 10.8% and a top mass of m{sub t} = 175 GeV/c2, the measured cross-section is [sigma](p{bar p} → t{bar t}) = 8.3 ± 1.3(stat.) ± 0.7(syst.) ± 0.5(lumi.) pb. The result is consistent with the Standard Model prediction of 6.7{sub -0.9}{sup +0.7} pb and represents a significant improvement in precision over previous results using this selection.

Measurement of the Top Quark Pair Production Cross-section in the Dilepton Channel Using Lepton Plus Track Selection and Identified B-jets

Measurement of the Top Quark Pair Production Cross-section in the Dilepton Channel Using Lepton Plus Track Selection and Identified B-jets PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Using 1.0 fb^{-1} of data collected by the Collider Detector at Fermilab (CDF) from Run II of the Fermilab Tevatron, we measure the top-antitop production cross-section in events with two leptons, significant missing transverse energy, and at least jets, at least one of which is identified as a b-jet. As the Run II dataset grows, more stringent tests of Standard Model predictions for the top quark sector are becoming possible. The dilepton channel, where both top quarks decay t-> W b ->l nu b, is of particular interest due to its high purity. Use of an isolated track as the second lepton significantly increases the dilepton acceptance, at the price of some increase in background, particularly from W + jets events where one of the jets is identified as a lepton. To control the increase in background we add to the event selection the requirement that at least one of the jets be identified as a b-jet, reducing the background contribution from all sources. Assuming a branching ratio of BR(W->l nu) = 10.8% and a top mass of m_top = 175 GeV/c^{2} the measured cross-section is sigma = (10.5 +/- 1.8 stat. +/- 0.8 syst. +/- 0.6 lumi.) pb.

Measurement of the Top Quark Pair Production Cross-Section in the Dilepton Channel Using Lepton Plus Track Selection and Identified B-jets

Measurement of the Top Quark Pair Production Cross-Section in the Dilepton Channel Using Lepton Plus Track Selection and Identified B-jets PDF Author: Teresa Spreitzer
Publisher:
ISBN: 9780494713709
Category :
Languages : en
Pages : 282

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Book Description
Using 1.0 fb-1 of data collected by the Collider Detector at Fermilab (CDF) from Run II of the Fermilab Tevatron, we measure the tt ̄ production cross-section in events with two leptons, significant missing transverse energy, and ≥ 2 jets, at least one of which is identified as a b-jet. As the Run II dataset grows, more stringent tests of Standard Model predictions for the top quark sector are becoming possible. The dilepton channel, where both top quarks decay t → Wb → ℓvb, is of particular interest due to its high purity. Use of an isolated Crack as the second lepton significantly increases the dilepton acceptance, at the price of some increase in background, particularly from W + jets events where one of the jets is identified as a lepton. To control the increase in background we add to the event selection the requirement that at least one of the jets be identified as a b-jet, reducing the background contribution from all sources. Assuming a branching ratio of BR(W → ℓ v) = 10.8 % and a top mass of mt = 175 GeV/c2 , the measured cross-section is sigma(pp → tt) = 10.5 +/- 1.8 (stat.) +/- 0.8 (syst. ) +/- 0.6 (lumi.) pb.

Top Pair Production in the Dilepton Decay Channel with a Tau Lepton

Top Pair Production in the Dilepton Decay Channel with a Tau Lepton PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 218

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Book Description
The top quark pair production and decay into leptons with at least one being a [tau] lepton is studied in the framework of the CDF experiment at the Tevatron proton antiproton collider at Fermilab (USA). The selection requires an electron or a muon produced either by the [tau] lepton decay or by a W decay. The analysis uses the complete Run II data set i.e. 9.0 fb-1, selected by one trigger based on a low transverse momentum electron or muon plus one isolated charged track. The top quark pair production cross section at 1.96 TeV is measured at 8.2 ± 1.7+1.2-1.1 ± 0.5 pb, and the top branching ratio into [tau] lepton is measured at 0.120 ± 0.027+0.022 -0.019 ± 0.007 with statistical, systematics and luminosity uncertainties. These are up to date the most accurate results in this top decay channel and are in good agreement with the results obtained using other decay channels of the top at the Tevatron. The branching ratio is also measured separating the single lepton from the two leptons events with a log likelihood method. This is the first time these two signatures are separately identified. With a fit to data along the log-likelihood variable an alternative measurement of the branching ratio is made: 0.098 ± 0.022(stat:) ± 0.014(syst:); it is in good agreement with the expectations of the Standard Model (with lepton universality) within the experimental uncertainties. The branching ratio is constrained to be less than 0.159 at 95% con dence level. This limit translates into a limit of a top branching ratio into a potential charged Higgs boson.

Fundamental Interactions - Proceedings Of The Nineteenth Lake Louise Winter Institute

Fundamental Interactions - Proceedings Of The Nineteenth Lake Louise Winter Institute PDF Author: Alan Astbury
Publisher: World Scientific
ISBN: 9814480681
Category : Science
Languages : en
Pages : 360

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Book Description
This volume contains pedagogical lectures on particle physics, nuclear astrophysics, relativistic heavy ion interactions and gravitational waves. In addition, numerous contributions provide up-to-date information on new experimental results at colliders, underground laboratories and nuclear astrophysics. This combination of pedagogical talks and topical short talks provide a comprehensive amount of information to the researchers.

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.

High Energy Physics

High Energy Physics PDF Author: Hesheng Chen
Publisher: World Scientific
ISBN: 9814481270
Category : Science
Languages : en
Pages : 1424

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Book Description
The 32nd International Conference on High Energy Physics belongs to the Rochester Conference Series, and is the most important international conference in 2004 on high energy physics. The proceedings provide a comprehensive review on the recent developments in experimental and theoretical particle physics. The latest results on Top, Higgs search, CP violation, neutrino mixing, pentaquarks, heavy quark mesons and baryons, search for new particles and new phenomena, String theory, Extra dimension, Black hole and Lattice calculation are discussed extensively. The topics covered include not only those of main interest to the high energy physics community, but also recent research and future plans. Contents: Neutrino Masses and MixingsQuark Matter and Heavy Ion CollisionsParticle Astrophysics and CosmologyElectroweak PhysicsQCD Hard InteractionsQCD Soft InteractionsComputational Quantum Field TheoryCP Violation, Rare Kaon Decay and CKMR&D for Future Accelerator and DetectorHadron Spectroscopy and ExoticsHeavy Quark Mesons and BaryonsBeyond the Standard ModelString Theory Readership: Experimental and theoretical physicists and graduate students in the fields of particle physics, nuclear physics, astrophysics and cosmology.Keywords:High Energy Physics;Particle Physics;Electroweak;QCD;Heavy Quark;Neutrino;Particle Astrophysics;Hadron Spectroscopy;CP Violation;Quark Matter;Future Accelerator

High Energy Physics 99 Proceedings of the International Europhysics Conference on High Energy Physics, Tampere, Finland, 15-21 July 1999

High Energy Physics 99 Proceedings of the International Europhysics Conference on High Energy Physics, Tampere, Finland, 15-21 July 1999 PDF Author: K Huitu
Publisher: CRC Press
ISBN: 9780750306614
Category : Science
Languages : en
Pages : 1112

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Book Description
High Energy Physics 99 contains the 18 invited plenary presentations and 250 contributions to parallel sessions presented at the International Europhysics Conference on High Energy Physics. The book provides a comprehensive survey of the latest developments in high energy physics. Topics discussed include hard high energy, structure functions, soft interactions, heavy flavor, the standard model, hadron spectroscopy, neutrino masses, particle astrophysics, field theory, and detector development.

Dissertation Abstracts International

Dissertation Abstracts International PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 980

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Book Description