TOP-14-004 "Differential measurement of the cross section of single top-quark production in the t-channel at 8 TeV"

Abstract

Measurements of differential single top quark t channel production cross sections in proton-proton collisions are presented. The differential cross sections are measured as functions of the transverse momentum and the absolute value of the rapidity of the top quark. The analysis is performed in the leptonic decay channels of the top quark, with either a muon or an electron in the final state, using data collected with the CMS experiment at the LHC at a centre-of-mass energy of 8TeV and corresponding to an integrated luminosity of 19.7/fb. Artificial neural networks are used to discriminate the signal process from the various background contributions. The results are found to agree with predictions from Monte Carlo generators.

Public Document

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Figures

Figure Caption
NN output distributions in the electron channel (2j1t signal region). The simulations of different processes are normalized to the fit results. (pdf)
NN output distributions in the electron channel (3j2t ttbar control region). The simulations of different processes are normalized to the fit results. (pdf)
NN output distributions in the muon channel (2j1t signal region). The simulations of different processes are normalized to the fit results. (pdf)
NN output distributions in the muon channel (3j2t ttbar control region). The simulations of different processes are normalized to the fit results. (pdf)
Distribution of the reconstructed top-quark pT in the combined lepton+jets channel (electron and muon channel combined) with the cut on the NN discriminators applied. The simulations of the different processes are normalized to the fit results. (pdf)
Distribution of the absolute value of the reconstructed top quark rapidity in the combined lepton+jets channel (electron and muon channel combined) with the cut on the NN discriminators applied. The simulations of the different processes are normalized to the fit results. (pdf)
Shape comparison of the transverse momentum of the single top quark on generator level without any selection, generated after selection cuts, and reconstructed after selection cuts in the combined lepton+jets channel. (pdf)
Shape comparison of the absolute value of the rapidity of the single top quark on generator level without any selection, generated after selection cuts, and reconstructed after selection cuts in the combined lepton+jets channel. (pdf)

Figures: Results

Figure Caption
Unfolded pT of the top quarks in the combined lepton+jets channel compared with the predictions from PowHeg+Pythia (solid), aMC@NLO+Pythia (dotted), and CompHEP (dashed). The inner error bars indicate the statistical uncertainty while the outer error bars indicate the full (stat. + syst.) uncertainty. (pdf)
Unfolded abs(y) spectrum of the top quarks in the combined lepton+jets channel compared with the predictions from PowHeg+Pythia (solid), aMC@NLO+Pythia (dotted), and CompHEP (dashed). The inner error bars indicate the statistical uncertainty while the outer error bars indicate the full (stat. + syst.) uncertainty. (pdf)

Tables

Table Caption
List of input variables used in the neural network training, ranked by relevance in the two channels.
Event yield in the muon (electron) channel for a cut on the NN output distribution of Discriminator>0.3 (0.4). The quoted uncertainties are the statistical uncertainties on the fit parameters.

-- AndreasMeyer - 29 Sep 2014

Topic attachments
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PNGpng Table1.png r1 manage 79.8 K 2014-09-26 - 18:37 ThorstenChwalek  
PNGpng Table2.png r1 manage 100.4 K 2014-09-26 - 18:37 ThorstenChwalek  
PDFpdf pt_Shape.pdf r1 manage 14.0 K 2014-09-26 - 19:05 ThorstenChwalek  
PNGpng pt_Shape.png r1 manage 26.5 K 2014-09-26 - 19:05 ThorstenChwalek  
PDFpdf pt_Stackplot.pdf r1 manage 17.8 K 2014-09-26 - 18:49 ThorstenChwalek  
PNGpng pt_Stackplot.png r1 manage 34.2 K 2014-09-26 - 18:49 ThorstenChwalek  
PDFpdf pt_unfolded.pdf r1 manage 16.4 K 2014-09-26 - 19:05 ThorstenChwalek  
PNGpng pt_unfolded.png r1 manage 35.3 K 2014-09-26 - 19:05 ThorstenChwalek  
PDFpdf stackplot_nnel2j1t.pdf r1 manage 19.1 K 2014-09-26 - 18:50 ThorstenChwalek  
PNGpng stackplot_nnel2j1t.png r1 manage 34.9 K 2014-09-26 - 18:50 ThorstenChwalek  
PDFpdf stackplot_nnel3j2t.pdf r1 manage 19.2 K 2014-09-26 - 18:50 ThorstenChwalek  
PNGpng stackplot_nnel3j2t.png r1 manage 34.1 K 2014-09-26 - 18:50 ThorstenChwalek  
PDFpdf stackplot_nnmu2j1t.pdf r1 manage 18.6 K 2014-09-26 - 18:50 ThorstenChwalek  
PNGpng stackplot_nnmu2j1t.png r1 manage 33.6 K 2014-09-26 - 18:50 ThorstenChwalek  
PDFpdf stackplot_nnmu3j2t.pdf r1 manage 20.3 K 2014-09-26 - 18:50 ThorstenChwalek  
PNGpng stackplot_nnmu3j2t.png r1 manage 35.6 K 2014-09-26 - 18:50 ThorstenChwalek  
PDFpdf y_Shape.pdf r1 manage 14.2 K 2014-09-26 - 19:05 ThorstenChwalek  
PNGpng y_Shape.png r1 manage 27.5 K 2014-09-26 - 19:05 ThorstenChwalek  
PDFpdf y_Stackplot.pdf r1 manage 17.5 K 2014-09-26 - 18:49 ThorstenChwalek  
PNGpng y_Stackplot.png r1 manage 31.9 K 2014-09-26 - 18:49 ThorstenChwalek  
PDFpdf y_unfolded.pdf r1 manage 16.5 K 2014-09-26 - 19:05 ThorstenChwalek  
PNGpng y_unfolded.png r1 manage 35.1 K 2014-09-26 - 19:05 ThorstenChwalek  
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