Measurement of the Top Pair Production Cross Section in the Dilepton Decay Channel in Ppbar Collisions at Sqrt S

Measurement of the Top Pair Production Cross Section in the Dilepton Decay Channel in Ppbar Collisions at Sqrt S
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Release: 2010
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A measurement of the t{bar t} production cross section in p{bar p} collisions at √s = 1.96 TeV using events with two leptons, missing transverse energy, and jets is reported. The data were collected with the CDF II Detector. The result in a data sample corresponding to an integrated luminosity 2.8 fb−1 is: [sigma]{sub t{bar t}} = 6.27 ± 0.739(stat) ± 0.63(syst) ± 0.39(lum) pb for an assumed top mass of 175 GeV/c2.

First Measurement of the Cross Section for Top-Quark Pair Production in Proton-Proton Collisions at $\sqrt{s}

First Measurement of the Cross Section for Top-Quark Pair Production in Proton-Proton Collisions at $\sqrt{s}
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Total Pages: 26
Release: 2011
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The first measurement of the cross section for top-quark pair production in pp collisions at the LHC at center-of-mass energy sqrt(s)= 7 TeV has been performed using 3.1 {\pm} 0.3 inverse pb of data recorded by the CMS detector. This result utilizes the final state with two isolated, highly energetic charged leptons, large missing transverse energy, and two or more jets. Backgrounds from Drell-Yan and non-W/Z boson production are estimated from data. Eleven events are observed in the data with 2.1 {\pm} 1.0 events expected from background. The measured cross section is 194 {\pm} 72 (stat.) {\pm} 24 (syst.) {\pm} 21 (lumi.) pb, consistent with next-to-leading order predictions.

Measurement of the $t\bar{t}$ Production Cross Section in Pp Collisions at $\sqrt{s}$

Measurement of the $t\bar{t}$ Production Cross Section in Pp Collisions at $\sqrt{s}$
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Total Pages: 21
Release: 2014
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The top-quark pair production cross section is measured in final states with one electron or muon and one hadronically decaying [tau] lepton from the process $t\bar{t}$ to (l[nu]l) ([tau][nu][tau]) $b\bar{b}$, where l = e, [mu]. The data sample corresponds to an integrated luminosity of 19.6 fb-1 collected with the CMS detector in proton-proton collisions at $\sqrt{s}$ =8 TeV. The measured cross section [sigma]$t\bar{t}$ = 257 ± 3 (stat) ± 24 (syst) ± 7 (lumi) pb, assuming a top-quark mass of 172.5 GeV, is consistent with the standard model prediction.

Measurement of the Top-antitop Production Cross Section in Pp Collisions at Sqrt(s)

Measurement of the Top-antitop Production Cross Section in Pp Collisions at Sqrt(s)
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Total Pages: 39
Release: 2011
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A measurement of the top-antitop production cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV has been performed at the LHC with the CMS detector. The analysis uses a data sample corresponding to an integrated luminosity of 36 inverse picobarns and is based on the reconstruction of the final state with one isolated, high transverse-momentum electron or muon and three or more hadronic jets. The kinematic properties of the events are used to separate the top-antitop signal from W+jets and QCD multijet background events. The measured cross section is 173 + 39 - 32 (stat. + syst.) pb, consistent with standard model expectations.

Measurement of the $\mathrm{ T \bar{t} }$ Production Cross Section in the $\mathrm{ E \mu }$ Channel in Proton-proton Collisions at $\sqrt{s}

Measurement of the $\mathrm{ T \bar{t} }$ Production Cross Section in the $\mathrm{ E \mu }$ Channel in Proton-proton Collisions at $\sqrt{s}
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Total Pages: 54
Release: 2016
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The inclusive cross section for top quark pair production is measured in proton-proton collisions at √s = 7 and 8 TeV, corresponding to 5.0 and 19.7 fb-1, respectively, with the CMS experiment at the LHC. The cross sections are measured in the electron-muon channel using a binned likelihood fit to multi-differential final state distributions related to identified b quark jets and other jets in the event. The measured cross section values are 173.6 ± 2.1 (stat)+4.5-4.0 (syst) ± 3.8 (lumi) pb at √s = 7 TeV, and 244.9 ± 1.4 (stat)+6.3-5.5 (syst) ± 6.4 (lumi) pb at √s = 8 TeV, in good agreement with QCD calculations at next-to-next-to-leading-order accuracy. The ratio of the cross sections measured at 7 and 8 TeV is determined, as well as cross sections in the fiducial regions defined by the acceptance requirements on the two charged leptons in the final state. The cross section results are used to determine the top quark pole mass via the dependence of the theoretically predicted cross section on the mass, giving a best result of 173.8+1.7-1.8 GeV. Furthermore, the data at √s = 8 TeV are also used to set limits, for two neutralino mass values, on the pair production of supersymmetric top squarks with masses close to the top quark mass.

Measurements of the Top - Anti-top Production Cross Section at S**(1/2)

Measurements of the Top - Anti-top Production Cross Section at S**(1/2)
Author: Joseph Francis Kozminski
Publisher:
Total Pages: 218
Release: 2005
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ISBN:

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The first measurement of the top-antitop production cross section in proton-antiproton collisions at {radical}s = 1.96 TeV using 243 pb{sup -1} of data collected with the D0 detector at Fermilab is presented. In this analysis, only the dielectron final state is considered. Five events are observed, and 0.93 background events are expected. The measured cross section, after accounting for the expected branching ratio to the dielectron channel, is {sigma}{sub t{bar t}} = 14.9{sub -7.0}{sup +9.4}(stat){sub -1.8}{sup +2.5}(syst) {+-} 1.0 (lumi) pb, which agrees with the predicted cross section for top quarks with a mass of 175 GeV. In addition, a first-pass at a measurement of the top mass using the neutrino-weighting method is presented. This measurement is also performed in the dielectron channel using the five events observed in the cross section measurement.