Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**(1/2)

Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**(1/2)
Title Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**(1/2) PDF eBook
Author Salvatore Rocco Rappoccio
Publisher
Pages 377
Release 2005
Genre
ISBN

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We present the measurement of the t{bar t} cross section in the lepton plus jets channel with {ge} 1 and {ge} 2 secondary vertex tags. We use the scalar sum of transverse energies of the event (H{sub T}) to discriminate t{bar t} from the other backgrounds. We also use the transverse mass of the leptonic W-boson (M{sub T}{sup W}) to further reduce the Non-W backgrounds. We use a combination of data and Monte Carlo to estimate the backgrounds from electroweak processes, single top, fake leptons, W+ Light Flavor fake tags, and real W+ Heavy Flavor production. We obtain a value of {sigma} {sub {ge}1} = 8.7{sub -0.9}{sup +0.9}(stat){sub -0.9}{sup +1.2}(sys) pb for the {ge}1 tag cross section, and {sigma}{sub {ge}2} = 8.7{sub -1.6}{sup +1.8}(stat){sub -1.3}{sup +1.9}(sys) pb for the {ge}2 tag cross section. The authors also present a measurement of the t{bar t} cross section by fitting the N{sub jet} spectrum. They combine the =1 and {ge}2 tag cross sections to obtain {sigma}{sub t{bar t}} = 8.9{sub -0.9}{sup +0.9}(stat){sub -1.3}{sup +1.4}(syst)pb.

A Measurement of the T Anti-t Cross Section in P Anti-p Collisions at S**1/2

A Measurement of the T Anti-t Cross Section in P Anti-p Collisions at S**1/2
Title A Measurement of the T Anti-t Cross Section in P Anti-p Collisions at S**1/2 PDF eBook
Author
Publisher
Pages 43
Release 2009
Genre
ISBN

Download A Measurement of the T Anti-t Cross Section in P Anti-p Collisions at S**1/2 Book in PDF, Epub and Kindle

This paper reports a measurement of the cross section for the pair production of top quarks in p{bar p} collisions at √s = 1.96 TeV at the Fermilab Tevatron. The data was collected from the CDF II detector in a set of runs with a total integrated luminosity of 1.1 fb−1. The cross section is measured in the dilepton channel, the subset of t{bar t} events in which both top quarks decay through t → Wb → l[nu]b, where l = e, [mu], or [tau]. The lepton pair is reconstructed as one identified electron or muon and one isolated track. The use of an isolated track to identify the second lepton increases the t{bar t} acceptance, particularly for the case in which one W decays as W → [tau][nu]. The purity of the sample may be further improved at the cost of a reduction in the number of signal events, by requiring an identified b-jet. They present the results of measurements performed with and without the request of an identified b-jet. the former is the first published CDF result for which a b-jet requirement is added to the dilepton selection. In the CDF data there are 129 pretag lepton + track candidate events, of which 69 are tagged. With the tagging information, the sample is divided into tagged and untagged sub-samples, and a combined cross section is calculated by maximizing a likelihood. The result is [sigma]{sub t{bar t}} = 9.6 ± 1.2(stat.){sub -0.5}{sup +0.6}(sys.) ± 0.6(lum.) pb, assuming a branching ratio of BR(W → l[nu]) = 10.8% and a top mass of m{sub t} = 175 GeV/c2.

Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**1/2

Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**1/2
Title Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**1/2 PDF eBook
Author
Publisher
Pages 7
Release 2005
Genre
ISBN

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We present a measurement of the top quark pair (t{bar t}) production cross section ([sigma]{sub t{bar t}}) in p{bar p} collisions at a center-of-mass energy of 1.96 TeV using 230 pb1 of data collected by the D0 detector at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), large missing transverse energy, and at least four jets, and extract the t{bar t} content of the sample based on the kinematic characteristics of the events. For a top quark mass of 175 GeV, we measure [sigma]{sub t{bar t}} = 6.7{sub -1.3}{sup +1.4}(stat){sub -1.1}{sup +1.6}(syst) ± 0.4(lumi)pb, in good agreement with the standard model prediction.

A Measurement of the T Anti-t Cross Section in P Anti-p Collisions at S**ư

A Measurement of the T Anti-t Cross Section in P Anti-p Collisions at S**ư
Title A Measurement of the T Anti-t Cross Section in P Anti-p Collisions at S**ư PDF eBook
Author
Publisher
Pages 43
Release 2009
Genre
ISBN

Download A Measurement of the T Anti-t Cross Section in P Anti-p Collisions at S**ư Book in PDF, Epub and Kindle

This paper reports a measurement of the cross section for the pair production of top quarks in p{bar p} collisions at √s = 1.96 TeV at the Fermilab Tevatron. The data was collected from the CDF II detector in a set of runs with a total integrated luminosity of 1.1 fb−1. The cross section is measured in the dilepton channel, the subset of t{bar t} events in which both top quarks decay through t → Wb → l?b, where l = e,?, or?. The lepton pair is reconstructed as one identified electron or muon and one isolated track. The use of an isolated track to identify the second lepton increases the t{bar t} acceptance, particularly for the case in which one W decays as W →??. The purity of the sample may be further improved at the cost of a reduction in the number of signal events, by requiring an identified b-jet. They present the results of measurements performed with and without the request of an identified b-jet. the former is the first published CDF result for which a b-jet requirement is added to the dilepton selection. In the CDF data there are 129 pretag lepton + track candidate events, of which 69 are tagged. With the tagging information, the sample is divided into tagged and untagged sub-samples, and a combined cross section is calculated by maximizing a likelihood. The result is?{sub t{bar t}} = 9.6 ± 1.2(stat.){sub -0.5}{sup +0.6}(sys.) ± 0.6(lum.) pb, assuming a branching ratio of BR(W → l?) = 10.8% and a top mass of m{sub t} = 175 GeV/c2.

A Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**1/2

A Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**1/2
Title A Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**1/2 PDF eBook
Author
Publisher
Pages 131
Release 2008
Genre
ISBN

Download A Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**1/2 Book in PDF, Epub and Kindle

I present a measurement of the t{bar t} production cross section at √s = 1.96 TeV using 2034 pb−1 of CDF Run II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes a t → Wb branching fraction of 100 percent. Events consistent with t{bar t} decay are found by identifying jets containing heavy-flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the data. Based on 248 candidate events and an expected background of 86.8 ± 5.6 events, I measure a production cross section of 8.7 ± 1.1{sub -0.8}{sup +0.9} ± 0.6 pb, in agreement with the Standard Model.

Measurement of the T Anti-t Production Cross-section in P Anti-p Collisions Using Dilepton Events

Measurement of the T Anti-t Production Cross-section in P Anti-p Collisions Using Dilepton Events
Title Measurement of the T Anti-t Production Cross-section in P Anti-p Collisions Using Dilepton Events PDF eBook
Author
Publisher
Pages 26
Release 2007
Genre
ISBN

Download Measurement of the T Anti-t Production Cross-section in P Anti-p Collisions Using Dilepton Events Book in PDF, Epub and Kindle

Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**ư

Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**ư
Title Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**ư PDF eBook
Author
Publisher
Pages 45
Release 2006
Genre
ISBN

Download Measurement of the T Anti-t Production Cross Section in P Anti-p Collisions at S**ư Book in PDF, Epub and Kindle

The authors present a measurement of the t{bar t} production cross section using events with one charged lepton and jets from p{bar p} collisions at a center-of-mass energy of 1.96 TeV. A b-tagging algorithm based on the probability of displaced tracks coming from the event interaction vertex is applied to identify b quarks from top decay. Using 318 pb−1 of data collected with the CDF II detector, they measure the t{bar t} production cross section in events with at least one restrictive (tight) b-tagged jet and obtain 8.9{sub -1.0}{sup +1.0}(stat.){sub -1.0}{sup +1.1}(syst.) pb. The cross section value assumes a top quark mass of m{sub t} is presented in the paper. This result is consistent with other CDF measurements of the t{bar t} cross section using different samples and analysis techniques, and has similar systematic uncertainties. They have also performed consistency checks by using the b-tagging probability function to vary the signal to background ratio and also using events that have at least two b-tagged jets.