Differential measurements of the charge asymmetry in top quark pair production

Abstract

The difference in angular distributions between top quarks and antiquarks, commonly referred to as the charge asymmetry, is measured in a dataset corresponding to an integrated luminosity of 5.0/fb, collected with the CMS detector at the LHC. In addition to the inclusive measurement, for the first time at the LHC also differential measurements of the charge asymmetry are performed. The invariant mass, the rapidity, and the transverse momentum of the ttbar system are sensitive to the different processes contributing to the overall charge asymmetry and are therefore chosen as differentiating variables. The measured inclusive asymmetry of A = 0.004 +- 0.010 (stat.) +- 0.012 (syst.) and the measured differential asymmetries are consistent with the predictions from the standard model.

Approved Results from TOP-10-030

Figure / Table Abbreviated Caption
Results for the numbers of events for background and ttbar contributions from fits to data, along with their statistical uncertainties. The uncertainties quoted for the single-top-quark and Z+jets backgrounds are related to the constraints used as input fpr the likelihood fit.
Comparison of the combined lepton+jets data with simulated contributions for the M3 distribution. The simulated signal and background contributions are normalized to the results of the BG fit. (pdf)
Comparison of the combined lepton+jets data with simulated contributions for the MET distribution. The simulated signal and background contributions are normalized to the results of the BG fit. (pdf)
Comparison of the combined lepton+jets data with simulated contributions for the Delta(y) distribution. The simulated signal and background contributions are normalized to the results of the BG fit (pdf)
Migration matrix between the generated and the reconstructed values in Delta(y), after the event selection. (pdf)
Migration matrix between the generated and the reconstructed values in Delta(y), after the event selection, for the differential measurement in mttbar. (pdf)
Selection efficiency as a function of the generated Delta(y), defined with respect to inclusive ttbar production. (pdf)
Selection efficiency as a function of the generated Delta(y) for the differential measurement in mttbar, defined with respect to inclusive ttbar production. (pdf)
Systematic uncertainties for the inclusive measurement of the charge asymmetry. Listed are the shifts induced by systematic uncertainties in the measurement on data.
The measured inclusive asymmetry at the different stages of the analysis and the corresponding theory prediction from the SM.
Unfolded inclusive Delta(y) distribution(pdf)
Corrected asymmetry as a function of yttbar. The measured values are compared to NLO calculations for the SM and to predictions from an effective field theory (EFT). The error bars on the differential asymmetry values indicate the satistitcl and systematic uncertainties.(pdf)
Corrected asymmetry as a function of pTttbar. The measured values are compared to NLO calculations for the SM and to predictions from an effective field theory (EFT). The error bars on the differential asymmetry values indicate the satistitcl and systematic uncertainties.(pdf)
Corrected asymmetry as a function of mttbar. The measured values are compared to NLO calculations for the SM and to predictions from an effective field theory (EFT). The error bars on the differential asymmetry values indicate the satistitcl and systematic uncertainties.(pdf)

-- ThorstenChwalek - 26-Feb-2012

Topic attachments
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PDFpdf 1d_sensvar_result.pdf r2 r1 manage 14.1 K 2012-02-28 - 14:43 ThorstenChwalek  
PNGpng 1d_sensvar_result.png r1 manage 13.9 K 2012-02-28 - 14:44 ThorstenChwalek  
PDFpdf 1dmigmatrix.pdf r1 manage 14.2 K 2012-02-26 - 12:51 ThorstenChwalek  
PNGpng 1dmigmatrix.png r1 manage 18.3 K 2012-02-26 - 12:51 ThorstenChwalek  
PDFpdf 1dseleff_1dplot.pdf r1 manage 13.1 K 2012-02-26 - 12:51 ThorstenChwalek  
PNGpng 1dseleff_1dplot.png r1 manage 11.1 K 2012-02-26 - 12:51 ThorstenChwalek  
PNGpng BGTable.PNG r2 r1 manage 81.4 K 2012-02-28 - 14:52 ThorstenChwalek  
PNGpng Results.PNG r1 manage 59.3 K 2012-02-26 - 13:07 ThorstenChwalek  
PDFpdf Stack_m3_l.pdf r2 r1 manage 15.1 K 2012-02-28 - 14:02 ThorstenChwalek  
PNGpng Stack_m3_l.png r2 r1 manage 18.8 K 2012-02-28 - 14:37 ThorstenChwalek  
PDFpdf Stack_met_l.pdf r2 r1 manage 17.1 K 2012-02-28 - 14:37 ThorstenChwalek  
PNGpng Stack_met_l.png r2 r1 manage 19.6 K 2012-02-28 - 14:37 ThorstenChwalek  
PNGpng Systematicstable.PNG r1 manage 107.0 K 2012-02-26 - 13:07 ThorstenChwalek  
PDFpdf diffasys_m.pdf r2 r1 manage 16.0 K 2012-02-28 - 14:39 ThorstenChwalek  
PNGpng diffasys_m.png r2 r1 manage 14.0 K 2012-02-28 - 14:39 ThorstenChwalek  
PDFpdf diffasys_pt.pdf r2 r1 manage 14.7 K 2012-02-28 - 14:40 ThorstenChwalek  
PNGpng diffasys_pt.png r2 r1 manage 12.9 K 2012-02-28 - 14:40 ThorstenChwalek  
PDFpdf diffasys_y.pdf r2 r1 manage 15.6 K 2012-02-28 - 14:40 ThorstenChwalek  
PNGpng diffasys_y.png r2 r1 manage 11.8 K 2012-02-28 - 14:40 ThorstenChwalek  
PDFpdf migmatrix_m.pdf r1 manage 24.2 K 2012-02-26 - 12:52 ThorstenChwalek  
PNGpng migmatrix_m.png r1 manage 39.9 K 2012-02-26 - 12:52 ThorstenChwalek  
PDFpdf seleff_m.pdf r1 manage 26.9 K 2012-02-26 - 12:52 ThorstenChwalek  
PNGpng seleff_m.png r1 manage 23.7 K 2012-02-26 - 12:52 ThorstenChwalek  
PDFpdf stackplot_diffabsy_ljets.pdf r2 r1 manage 15.0 K 2012-02-28 - 14:38 ThorstenChwalek  
PNGpng stackplot_diffabsy_ljets.png r2 r1 manage 17.0 K 2012-02-28 - 14:38 ThorstenChwalek  
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Topic revision: r3 - 2012-03-03 - RobertoTenchini
 
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