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Book Measurements of the T tbar Production Cross Section in Lepton jets Final States in Pp Collisions at 8 TeV and Ratio of 8 to 7 TeV Cross Sections

Download or read book Measurements of the T tbar Production Cross Section in Lepton jets Final States in Pp Collisions at 8 TeV and Ratio of 8 to 7 TeV Cross Sections written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the top quark pair production (t-tbar) cross section in proton-proton collisions at the centre-of-mass energy of 8 TeV is presented using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.6 inverse-femtobarns. This analysis is performed in the t-tbar decay channels with one isolated, high transverse momentum electron or muon and at least four jets, at least one of which is required to be identified as originating from hadronization of a b quark. The calibration of the jet energy scale and the efficiency of b jet identification are determined from data. The measured t-tbar cross section is 228.5 +/- 3.8 (stat) +/- 13.7 (syst) +/- 6.0 (lumi) pb. This measurement is compared with an analysis of 7 TeV data, corresponding to an integrated luminosity of 5.0 inverse-femtobarns, to determine the ratio of 8 TeV to 7 TeV cross sections, which is found to be 1.43 +/- 0.04 (stat) +/- 0.07 (syst) +/- 0.05 (lumi). The measurements are in agreement with QCD predictions up to next-to-next-to-leading order.

Book Measurements of the Tt   Production Cross Section in Lepton jets Final States in Pp Collisions at 8 TeV and Ratio of 8 to 7 TeV Cross Sections

Download or read book Measurements of the Tt Production Cross Section in Lepton jets Final States in Pp Collisions at 8 TeV and Ratio of 8 to 7 TeV Cross Sections written by CMS Collaboration and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Measurement of the Ttbar Production Cross Section in the All jets Final State in Pp Collisions at   sqrt s

Download or read book Measurement of the Ttbar Production Cross Section in the All jets Final State in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cross section for tt production in the all-jets final state is measured in pp collisions at a centre-of-mass energy of 8 TeV at the LHC with the CMS detector, in data corresponding to an integrated luminosity of 18.4 fb-1. The inclusive cross section is found to be 275.6 ±6.1 (stat) ± 37.8 (syst) ± 7.2 (lumi) pb. The normalized differential cross sections are measured as a function of the top quark transverse momenta, pT, and compared to predictions from quantum chromodynamics. The results are reported at detector, parton, and particle levels. In all cases, the measured top quark pT spectra are significantly softer than theoretical predictions.

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

Download or read book Measurement of the T Anti t Production Cross Section in P Anti p Collisions at S 1 2 written by Salvatore Rocco Rappoccio and published by . This book was released on 2005 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Book Measurement of the Tt   Production Cross Section in Pp   Collisions at  square Root  S

Download or read book Measurement of the Tt Production Cross Section in Pp Collisions at square Root S written by Heather L. Ray and published by . This book was released on 2004 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Erratum to

    Book Details:
  • Author :
  • Publisher :
  • Release : 2015
  • ISBN :
  • Pages : 29 pages

Download or read book Erratum to written by and published by . This book was released on 2015 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: Table 4 was incorrectly captioned in the originally published version. The correct caption is 'Normalised differential tt- production cross section as a function of the number of additional jets with pT> 30 GeV in the lepton+jets channel. Furthermore, the statistical, systematic, and total uncertainties are also shown. Finally, the main experimental and model systematic uncertainties are displayed: JES and the combination of renormalisation and factorisation scales, jet-parton matching threshold, and hadronisation (in the table "Q2/Match./Had.")'.

Book Measurement of the  t bar t   Production Cross Section in Pp Collisions at   sqrt s

Download or read book Measurement of the t bar t Production Cross Section in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Book Measurement of the  t bar t   Production Cross Section Using Events with One Lepton and at Least One Jet in Pp Collisions at   sqrt s

Download or read book Measurement of the t bar t Production Cross Section Using Events with One Lepton and at Least One Jet in Pp Collisions at sqrt s written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the $\mathrm{ t \bar{t} }$ production cross section at $\sqrt{s}=$ 13 TeV is presented using proton-proton collisions, corresponding to an integrated luminosity of 2.3 fb$^{-1}$, collected with the CMS detector at the LHC. Final states with one isolated charged lepton (electron or muon) and at least one jet are selected and categorized according to the accompanying jet multiplicity. From a likelihood fit to the invariant mass distribution of the isolated lepton and a jet identified as coming from the hadronization of a bottom quark, the cross section is measured to be $\sigma(\mathrm{ t \bar{t} })=$ 835 $\pm$ 3 (stat) $\pm$ 23 (syst) $\pm$ 23 (lumi) pb, in agreement with the standard model prediction. Using the expected dependence of the cross section on the pole mass of the top quark ($m_{\mathrm{ t }}$), the value of $m_{\mathrm{ t }}$ is found to be 172.7$^{+2.4}_{-2.7}$ GeV.

Book Measurement of the Cross Section for T Anti t Production in P Anti p Collisions Using the Kinematics of Lepton   Jets Events

Download or read book Measurement of the Cross Section for T Anti t Production in P Anti p Collisions Using the Kinematics of Lepton Jets Events written by and published by . This book was released on 2005 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of the top pair production cross section in p{bar p} collisions at √s = 1.96 TeV. We collect a data sample with an integrated luminosity of 194 ± 11 pb−1 with the CDF II detector at the Fermilab Tevatron. We use an artificial neural network technique to discriminate between top pair production and background processes in a sample of 519 lepton + jets events, which have one isolated energetic charged lepton, large missing transverse energy and at least three energetic jets. We measure the top pair production cross section to be [sigma]{sub t{bar t}} = 6.6 ± 1.1 ± 1.5 pb, where the first uncertainty is statistical and the second is systematic.

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

Download or read book Measurement of the T Anti t Production Cross Section in P Anti p Collisions at S 1 2 written by Lucio Cerrito and published by . This book was released on 2005 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present two measurements of the t{bar t} production cross section in collisions of protons and antiprotons at {radical}s = 196 TeV. We analyze a dataset of 310 {+-} 20 pb{sup -1} collected with the CDF 2 detector. In the first measurement, we select events with six to eight jets, at least one of which having a displaced secondary vertex, little or no missing transverse energy and optimized kinematical criteria consistent with the t{bar t} all-hadronic decay channel. In the second measurement, we select events with four or more jets, at least one of which having a displaced secondary vertex, high missing transverse energy, and optimized kinematical criteria consistent with the decay of t{bar t} to {tau}+jets. The averaged t{bar t} production cross section, determined from six different measurements using the CDF 2 detector in the dilepton, lepton+jets and all-hadronic decay channels, is also calculated to be {sigma}{sub t{bar t}} = 7.1 {+-} 0.6(stat) {+-} 0.7(syst) {+-} 0.4(lumi) pb, in agreement with the prediction of the standard model.

Book Measurement of the T  bar t   Production Cross Section in P  bar p   Collisions at  u221A s

Download or read book Measurement of the T bar t Production Cross Section in P bar p Collisions at u221A s written by and published by . This book was released on 2005 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the measurement of the t$ar{t}$ cross section in the lepton plus jets channel with ≥ 1 and ≥ 2 secondary vertex tags. We use the scalar sum of transverse energies of the event (HT) to discriminate t{bar t} from the other backgrounds. We also use the transverse mass of the leptonic W-boson (M$Wtop{T}$) 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 ? ≥1 = 8.7$+0.9top{-0.9}$(stat)$+1.2top{-0.9}$(sys) pb for the ≥1 tag cross section, and ? ≥2 = 8.7$+1.8top{-1.6}$(stat)$+1.9top{-1.3}$(sys) pb for the ≥2 tag cross section. The authors also present a measurement of the t$ar{t}$ cross section by fitting the Njet spectrum. They combine the =1 and ≥2 tag cross sections to obtain ?t$ar{t}$ = 8.9$+0.9top{-0.9}$(stat)$+1.4top{-1.3}$(syst)pb.

Book   Top Physics

    Book Details:
  • Author :
  • Publisher :
  • Release : 2005
  • ISBN :
  • Pages : pages

Download or read book Top Physics written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the t{bar t} production cross section using 194 pb−1 of CDF II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes 100% t --> Wb branching fraction. 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 20 candidate events and an expected background of 9.5 " 1.1 events, we measure a production cross section of 5.3 " 3.3{sub -1.0}{sup +1.3} pb, in agreement with the standard model.

Book Measurement of the T Anti t Production Cross Section in P Anti p Collisions at S

Download or read book Measurement of the T Anti t Production Cross Section in P Anti p Collisions at S written by and published by . This book was released on 2005 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present two measurements of the t{bar t} production cross section in collisions of protons and antiprotons at √s = 196 TeV. We analyze a dataset of 310 ± 20 pb−1 collected with the CDF 2 detector. In the first measurement, we select events with six to eight jets, at least one of which having a displaced secondary vertex, little or no missing transverse energy and optimized kinematical criteria consistent with the t{bar t} all-hadronic decay channel. In the second measurement, we select events with four or more jets, at least one of which having a displaced secondary vertex, high missing transverse energy, and optimized kinematical criteria consistent with the decay of t{bar t} to?+jets. The averaged t{bar t} production cross section, determined from six different measurements using the CDF 2 detector in the dilepton, lepton+jets and all-hadronic decay channels, is also calculated to be?{sub t{bar t}} = 7.1 ± 0.6(stat) ± 0.7(syst) ± 0.4(lumi) pb, in agreement with the prediction of the standard model.

Book Measurement of the Top antitop Production Cross Section in Pp Collisions at Sqrt s

Download or read book Measurement of the Top antitop Production Cross Section in Pp Collisions at Sqrt s written by and published by . This book was released on 2011 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.