Top pair cross section in e/mu+jets at 8 TeV

Abstract

A measurement is presented of the top quark pair-production cross section in proton-proton collisions using data corresponding to an integrated luminosity of up to , collected by the CMS detector at the Large Hadron Collider.

The analysis is performed in the top quark pair decay channel with one isolated, high transverse momentum electron or muon, and at least four hadronic jets. At least one jet is required to originate from a b-quark.

The inclusive cross section is: , in agreement with QCD predictions up to approximate next-to-next-to-leading order.

Approved results from TOP-12-006 (click on result to get .png)

Result Channel
Fitted ttbar cross section for the electron+jets channel PDF
Fitted ttbar cross section for the muon+jets channel PDF
Fitted ttbar cross section for the combined channel PDF

Approved plots and tables

Figure Abbreviated caption
Jet-lepton mass distribution after JPM b tag on the leptonic b candidate in the mu+jets channel. Out of the box MC cross sections are used and the simulation is corrected for the measured b tagging efficiency. The uncertainty on the luminosity as well as the uncertainty on the b tagging is added to the uncertainty band. PDF PNG

Jet-lepton mass distribution after JPM b tag on the leptonic b candidate using signal (ttbar) and background normalisation from the template fit in the mu+jets channel. The W+jets background template from 7TeV is used. PDF PNG

Jet-lepton mass distribution after JPM b tag on the leptonic b candidate in the e+jets channel. Out of the box MC cross sections are used and the simulation is corrected for the measured b tagging efficiency. The uncertainty on the luminosity as well as the uncertainty on the b tagging is added to the uncertainty band. PDF PNG

Jet-lepton mass distribution after JPM b tag on the leptonic b candidate using signal (ttbar) and background normalisation from the template fit in the e+jets channel. The W+jets background template from 7TeV is used. PDF PNG

Systematics table for the combined fit. PDF PNG

Approved results from TOP-12-006 (alternative approach) (click on result to get .png)

As a cross-check, the M3 distribution is used for the binned likelihood fit. The M3 mass of the three-jet combination with the highest in the event is related to the hadronic top mass.

Approved plots and tables (click on image to get .png)

Figure Abbreviated caption
Result of the M3 template likelihood fit to 2012 data for the combined channel.PDF PNG

-- BenjaminKlein - 01-Jul-2012

Topic attachments
I Attachment History Action Size Date Who Comment
PDFpdf FitResult_electronChannel.pdf r1 manage 17.7 K 2012-07-02 - 08:40 MichaelMaes  
PNGpng FitResult_electronChannel.png r1 manage 19.1 K 2012-07-02 - 08:40 MichaelMaes  
PDFpdf FitResult_muonChannel.pdf r1 manage 17.8 K 2012-07-02 - 08:40 MichaelMaes  
PNGpng FitResult_muonChannel.png r1 manage 19.4 K 2012-07-02 - 08:40 MichaelMaes  
PNGpng M3_new.png r1 manage 53.3 K 2012-07-04 - 11:27 BenjaminKlein  
PDFpdf MLB_btag_El.pdf r3 r2 r1 manage 27.2 K 2012-07-04 - 14:42 MichaelMaes  
PNGpng MLB_btag_El.png r3 r2 r1 manage 31.5 K 2012-07-04 - 14:42 MichaelMaes  
PDFpdf MLB_btag_Mu.pdf r3 r2 r1 manage 27.9 K 2012-07-04 - 14:42 MichaelMaes  
PNGpng MLB_btag_Mu.png r3 r2 r1 manage 31.7 K 2012-07-04 - 14:42 MichaelMaes  
PDFpdf fit_result_combined_M3.pdf r4 r3 r2 r1 manage 19.4 K 2012-07-04 - 16:11 SilviaCostantini  
PNGpng fit_result_combined_M3.png r6 r5 r4 r3 r2 manage 53.8 K 2012-07-04 - 16:43 BenjaminKlein  
PDFpdf sigma_M3_combined.pdf r1 manage 20.2 K 2012-07-01 - 11:12 BenjaminKlein M3 cross section values
PNGpng sigma_M3_combined.png r1 manage 2.2 K 2012-07-01 - 11:12 BenjaminKlein M3 cross section values
PDFpdf sigma_M3_electron.pdf r1 manage 20.4 K 2012-07-01 - 11:12 BenjaminKlein M3 cross section values
PNGpng sigma_M3_electron.png r1 manage 2.2 K 2012-07-01 - 11:12 BenjaminKlein M3 cross section values
PDFpdf sigma_M3_muon.pdf r1 manage 20.6 K 2012-07-01 - 11:12 BenjaminKlein M3 cross section values
PNGpng sigma_M3_muon.png r1 manage 2.2 K 2012-07-01 - 11:12 BenjaminKlein M3 cross section values
PDFpdf sigma_Mlb_combined.pdf r1 manage 18.9 K 2012-07-01 - 12:13 BenjaminKlein cross sections Mlb method
PNGpng sigma_Mlb_combined.png r1 manage 2.9 K 2012-07-01 - 12:13 BenjaminKlein cross sections Mlb method
PDFpdf sigma_Mlb_electron.pdf r1 manage 18.5 K 2012-07-01 - 12:13 BenjaminKlein cross sections Mlb method
PNGpng sigma_Mlb_electron.png r1 manage 2.7 K 2012-07-01 - 12:13 BenjaminKlein cross sections Mlb method
PDFpdf sigma_Mlb_muon.pdf r1 manage 18.8 K 2012-07-01 - 12:13 BenjaminKlein cross sections Mlb method
PNGpng sigma_Mlb_muon.png r1 manage 2.7 K 2012-07-01 - 12:13 BenjaminKlein cross sections Mlb method
PDFpdf syst_table_combined.pdf r1 manage 52.7 K 2012-07-02 - 09:26 MichaelMaes systematics table for the reference result
PNGpng syst_table_combined.png r1 manage 54.8 K 2012-07-02 - 09:26 MichaelMaes systematics table for the reference result
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Topic revision: r12 - 2012-07-04 - BenjaminKlein
 
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