TOP-12-038
Measurement of the single-top t-channel charge ratio at 8 TeV

Abstract

This note presents a measurement of the top and anti-top production ratio in single top t-channel processes at 8 TeV with the CMS detector at the LHC. A selection exploiting the t-channel topology is performed. Events are selected with the top decaying either into an inclusive muon or electron. The main backgrounds are evaluated through data-driven techniques. The distribution of pseudorapidity of the recoil quark is exploited to extract the signal simultaneously in the events with positively and negatively charged leptons. The separate top and anti-top cross sections measurements yield σ t-ch., top; = 49.9 9.1 pb and σt-ch., anti-top; = 28.3 5.5 pb respectively. The measured ratio is Rt-ch. = σt-ch., topt-ch., anti-top; = 1.76 0.27, in agreement with the standard model predictions.

Public Document

The document CMS-PAS-TOP-12-038 will arrive soon.

Results

$\sigma ( t-channel, top, 8TeV) = 49.9 \pm 1.9 (stat.) \pm 8.9 (syst.) pb $

$\sigma ( t-channel, anti-top, 8TeV) = 28.8 \pm 2.4 (stat.) \pm 4.9 (syst.) pb $

$ |R_{t-channel}| = 1.76 \pm 0.15 (stat.) \pm 0.22 (syst.) $

Figures

Figure Caption
Ratio.png Measured ratio of t-channel single-top and single-antitop cross section, compared with the values obtained using different pdf sets. The uncertainties include the factorisation and renormalisation scales and top mass uncertainties. [pdf]
SR1etaNoVeto10BinsTTFitFixRemodelConstrMuStack_Plus.png   ηj′ distribution for muons in the 2-jets 1-tag signal sample after normalizing each process contribution to the results of the simultaneous fit to ηj′ . Positive charge only.[pdf]
SR1etaNoVeto10BinsTTFitFixRemodelConstrMuStack_Minus.png   ηj′ distribution for muons in the 2-jets 1-tag signal sample after normalizing each process contribution to the results of the simultaneous fit to ηj′ . Negative charge only.[pdf]
SR1etaNoVeto10BinsTTFitFixRemodelConstrEleStack_Plus.png   ηj′ distribution for electrons in the 2-jets 1-tag signal sample after normalizing each process contribution to the results of the simultaneous fit to ηj′ .Positive charge only. [pdf]
SR1etaNoVeto10BinsTTFitFixRemodelConstrEleStack_Minus.png   ηj′ distribution for electrons in the 2-jets 1-tag signal sample after normalizing each process contribution to the results of the simultaneous fit to ηj′ . Negative charge only. [pdf]
3J_1T_noSyst_DDNorm_etalj_MuStack.png   ηj′ distribution for muons in the 3-jets 1-tag control sample after normalizing each process contribution to the results of the simultaneous fit to ηj′ . [pdf]
3J_1T_noSyst_DDNorm_etalj_EleStack.png   ηj′ distribution for electrons in the 3-jets 1-tag control sample after normalizing each process contribution to the results of the simultaneous fit to ηj′ . [pdf]
3J_2T_noSyst_DDNorm_etalj_MuStack.png   ηj′ distribution for muons in the 3-jets 2-tags control sample after normalizing each process contribution to the results of the simultaneous fit to ηj′ . [pdf]
3J_2T_noSyst_DDNorm_etalj_EleStack.png   ηj′ distribution for electrons in the 3-jets 2-tags control sample after normalizing each process contribution to the results of the simultaneous fit to ηj′ . [pdf]
2J_0T_noSyst_etalj_inclusiveMuStack.png   ηj′ distribution for muons in the 2-jets 0-tags control sample after normalizing each process contribution to the results of the fit to the w transverse mass mT performed to measure the qcd yield. [pdf]
2J_0T_noSyst_etalj_inclusiveEleStack.png   ηj′ distribution for electrons in the 2-jets 0-tags control sample after normalizing each process contribution to the results of the fit to the w transverse mass mT performed to measure the qcd yield. [pdf]
fitMTMu.png Fit to the mT in the 2-jets 1-tag sample for muons. [pdf]
fitMETEle.png Fit to the ET, miss in the 2-jets 1-tag sample for electrons. [pdf]
charge_2J0T_Mu.png Muon charge in the 2-jets 0-tags sample normalizing to the data yield.[pdf]
charge_2J0T_Ele.png Electron charge in the 2-jets 0-tags sample normalizing to the data yield.[pdf]
3J_1T_noSyst_DDNorm_charge_MuStack.png Muon charge in the 3-jets 1-tag sample normalizing to the data yield.[pdf]
3J_1T_noSyst_DDNorm_charge_EleStack.png Electron charge in the 3-jets 1-tag sample normalizing to the data yield.[pdf]
3J_2T_noSyst_DDNorm_charge_MuStack.png Muon charge in the 3-jets 2-tags sample normalizing to the data yield.[pdf]
3J_2T_noSyst_DDNorm_charge_EleStack.png Electron charge in the 3-jets 2-tags sample normalizing to the data yield.[pdf]

Tables

EventsSRSB.png Expected and observed number of events in the 2-jets 1 tag sample, in the signal signal and sideband region for positively and negatively charged muons. Only statistical uncertainties are shown. All numbers refer to MC expectation except for the QCD and W/Z+jets, for which the data-driven estimate is used.

EventsSRSBEle.png Expected and observed number of events in the 2-jets 1 tag sample, in the signal signal and sideband region for positively and negatively charged electrons. Only statistical uncertainties are shown. All numbers refer to MC expectation except for the QCD and W/Z+jets, for which the data-driven estimate is used.

SystTable.png Breakdown of the uncertainties on the t-channel single-top, single-ant-top cross section and on the ratio.
Topic attachments
I Attachment HistorySorted ascending Action Size Date Who Comment
PDFpdf 2J_0T_noSyst_etalj_inclusiveEleStack.pdf r1 manage 25.0 K 2013-03-06 - 11:31 AlbertoOrsoMariaIorio inclusive jet eta in the 2-jets 0-tags, electrons
PNGpng 2J_0T_noSyst_etalj_inclusiveEleStack.png r1 manage 18.6 K 2013-03-06 - 11:31 AlbertoOrsoMariaIorio inclusive jet eta in the 2-jets 0-tags, electrons
PDFpdf 2J_0T_noSyst_etalj_inclusiveMuStack.pdf r1 manage 24.7 K 2013-03-06 - 11:30 AlbertoOrsoMariaIorio inclusive jet eta in the 2-jets 0-tags, muons
PNGpng 2J_0T_noSyst_etalj_inclusiveMuStack.png r1 manage 17.8 K 2013-03-06 - 11:29 AlbertoOrsoMariaIorio inclusive jet eta in the 2-jets 0-tags, muons
PDFpdf 3J_1T_noSyst_DDNorm_charge_EleStack.pdf r1 manage 16.1 K 2013-03-06 - 12:17 AlbertoOrsoMariaIorio lepton charge in the 3-jets 1-tag sample, electrons
PNGpng 3J_1T_noSyst_DDNorm_charge_EleStack.png r1 manage 13.0 K 2013-03-06 - 12:07 AlbertoOrsoMariaIorio lepton charge in the 3-jets 1-tag sample, electrons
PDFpdf 3J_1T_noSyst_DDNorm_charge_MuStack.pdf r1 manage 16.4 K 2013-03-06 - 12:12 AlbertoOrsoMariaIorio lepton charge in the 3-jets 1-tag sample, muons
PNGpng 3J_1T_noSyst_DDNorm_charge_MuStack.png r1 manage 13.4 K 2013-03-06 - 12:07 AlbertoOrsoMariaIorio lepton charge in the 3-jets 1-tag sample, muons
PDFpdf 3J_1T_noSyst_DDNorm_etalj_EleStack.pdf r1 manage 25.9 K 2013-03-06 - 11:34 AlbertoOrsoMariaIorio light jet eta in the 3-jets 1-tag, electrons
PNGpng 3J_1T_noSyst_DDNorm_etalj_EleStack.png r1 manage 18.8 K 2013-03-06 - 11:34 AlbertoOrsoMariaIorio light jet eta in the 3-jets 1-tag, electrons
PDFpdf 3J_1T_noSyst_DDNorm_etalj_MuStack.pdf r1 manage 24.8 K 2013-03-06 - 11:32 AlbertoOrsoMariaIorio light jet eta in the 3-jets 1-tag, muons
PNGpng 3J_1T_noSyst_DDNorm_etalj_MuStack.png r1 manage 17.4 K 2013-03-06 - 11:32 AlbertoOrsoMariaIorio light jet eta in the 3-jets 1-tag, muons
PDFpdf 3J_2T_noSyst_DDNorm_charge_EleStack.pdf r1 manage 16.6 K 2013-03-06 - 12:19 AlbertoOrsoMariaIorio lepton charge in the 3-jets 2-tags sample, electrons
PNGpng 3J_2T_noSyst_DDNorm_charge_EleStack.png r1 manage 13.6 K 2013-03-06 - 12:19 AlbertoOrsoMariaIorio lepton charge in the 3-jets 2-tags sample, electrons
PDFpdf 3J_2T_noSyst_DDNorm_charge_MuStack.pdf r1 manage 16.4 K 2013-03-06 - 12:10 AlbertoOrsoMariaIorio lepton charge in the 3-jets 2-tags sample, muons
PNGpng 3J_2T_noSyst_DDNorm_charge_MuStack.png r1 manage 12.3 K 2013-03-06 - 12:13 AlbertoOrsoMariaIorio lepton charge in the 3-jets 2-tags sample, muons
PDFpdf 3J_2T_noSyst_DDNorm_etalj_EleStack.pdf r1 manage 25.9 K 2013-03-06 - 11:40 AlbertoOrsoMariaIorio light jet eta in the 3-jets 2-tags, electrons
PNGpng 3J_2T_noSyst_DDNorm_etalj_EleStack.png r1 manage 18.0 K 2013-03-06 - 11:40 AlbertoOrsoMariaIorio light jet eta in the 3-jets 2-tags, electrons
PDFpdf 3J_2T_noSyst_DDNorm_etalj_MuStack.pdf r1 manage 25.1 K 2013-03-06 - 11:39 AlbertoOrsoMariaIorio light jet eta in the 3-jets 2-tags, muons
PNGpng 3J_2T_noSyst_DDNorm_etalj_MuStack.png r1 manage 17.2 K 2013-03-06 - 11:39 AlbertoOrsoMariaIorio light jet eta in the 3-jets 2-tags, muons
PNGpng CrossSec.png r1 manage 13.3 K 2013-03-06 - 16:24 AlbertoOrsoMariaIorio Measured cross section for t-channel top, anti-top and their ratio.
PNGpng CrossSecAnti.png r1 manage 15.3 K 2013-03-06 - 16:24 AlbertoOrsoMariaIorio Measured cross section for t-channel top, anti-top and their ratio.
PNGpng EventsSRSB.png r1 manage 82.4 K 2013-03-06 - 16:17 AlbertoOrsoMariaIorio Event yield, muons
PNGpng EventsSRSBEle.png r1 manage 83.0 K 2013-03-06 - 16:18 AlbertoOrsoMariaIorio Event yield, electrons
PNGpng R.png r1 manage 12.0 K 2013-03-06 - 16:24 AlbertoOrsoMariaIorio Measured cross section for t-channel top, anti-top and their ratio.
PDFpdf Ratio.pdf r1 manage 14.0 K 2013-03-06 - 12:52 AlbertoOrsoMariaIorio Top-antitop ratio with different pdf models
PNGpng Ratio.png r1 manage 38.7 K 2013-03-06 - 12:52 AlbertoOrsoMariaIorio Top-antitop ratio with different pdf models
PDFpdf SR1etaNoVeto10BinsTTFitFixRemodelConstrEleStack_Minus.pdf r1 manage 17.9 K 2013-03-06 - 12:41 AlbertoOrsoMariaIorio light jet eta, 2-jets 1-tag sample fit results, negative electrons
PNGpng SR1etaNoVeto10BinsTTFitFixRemodelConstrEleStack_Minus.png r1 manage 14.8 K 2013-03-06 - 12:41 AlbertoOrsoMariaIorio light jet eta, 2-jets 1-tag sample fit results, negative electrons
PDFpdf SR1etaNoVeto10BinsTTFitFixRemodelConstrEleStack_Plus.pdf r1 manage 17.8 K 2013-03-06 - 12:36 AlbertoOrsoMariaIorio light jet eta, 2-jets 1-tag sample fit results, positive electrons
PNGpng SR1etaNoVeto10BinsTTFitFixRemodelConstrEleStack_Plus.png r1 manage 14.9 K 2013-03-06 - 12:36 AlbertoOrsoMariaIorio light jet eta, 2-jets 1-tag sample fit results, positive electrons
PDFpdf SR1etaNoVeto10BinsTTFitFixRemodelConstrMuStack_Minus.pdf r1 manage 17.5 K 2013-03-06 - 12:35 AlbertoOrsoMariaIorio light jet eta, 2-jets 1-tag sample fit results, negative muons
PNGpng SR1etaNoVeto10BinsTTFitFixRemodelConstrMuStack_Minus.png r1 manage 13.7 K 2013-03-06 - 12:35 AlbertoOrsoMariaIorio light jet eta, 2-jets 1-tag sample fit results, negative muons
PDFpdf SR1etaNoVeto10BinsTTFitFixRemodelConstrMuStack_Plus.pdf r1 manage 17.8 K 2013-03-06 - 12:34 AlbertoOrsoMariaIorio light jet eta, 2-jets 1-tag sample fit results, positive muons
PNGpng SR1etaNoVeto10BinsTTFitFixRemodelConstrMuStack_Plus.png r1 manage 14.3 K 2013-03-06 - 12:34 AlbertoOrsoMariaIorio light jet eta, 2-jets 1-tag sample fit results, positive muons
PNGpng SystTable.png r1 manage 107.1 K 2013-03-06 - 16:18 AlbertoOrsoMariaIorio Uncertainties breakdown
PDFpdf charge_2J0T_Ele.pdf r1 manage 16.5 K 2013-03-06 - 11:44 AlbertoOrsoMariaIorio lepton charge in the 2-jets 0-tags sample, electrons
PDFpdf charge_2J0T_Mu.pdf r1 manage 16.3 K 2013-03-06 - 11:44 AlbertoOrsoMariaIorio lepton charge in the 2-jets 0-tags sample, muons
PNGpng fitMETEle.png r1 manage 43.8 K 2013-03-06 - 13:05 AlbertoOrsoMariaIorio MET fit in the 2-jets 1-tag sample, electrons
PNGpng fitMTMu.png r1 manage 42.6 K 2013-03-06 - 13:04 AlbertoOrsoMariaIorio MT fit in the 2-jets 1-tag sample, muons
PDFpdf testFitMTWDataQCDAntiIso_Ele.pdf r1 manage 19.6 K 2013-03-06 - 13:05 AlbertoOrsoMariaIorio MET fit in the 2-jets 1-tag sample, electrons
PDFpdf testFitMTWDataQCDAntiIso_Mu.pdf r1 manage 19.5 K 2013-03-06 - 13:04 AlbertoOrsoMariaIorio MT fit in the 2-jets 1-tag sample, muons
PNGpng charge_2J0T_Ele.png r2 r1 manage 75.4 K 2013-03-06 - 12:05 AlbertoOrsoMariaIorio lepton charge in the 2-jets 0-tags sample, electrons
PNGpng charge_2J0T_Mu.png r2 r1 manage 67.0 K 2013-03-06 - 12:06 AlbertoOrsoMariaIorio lepton charge in the 2-jets 0-tags sample, muons
Edit | Attach | Watch | Print version | History: r4 < r3 < r2 < r1 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r4 - 2013-11-23 - FerdosRezaei
 
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    CMSPublic All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2020 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback