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Compact Muon Solenoid
LHC, CERN

CMS-PAS-TOP-14-012
Measurement of the differential $ \mathrm{ t \bar{t} } $ production cross section for high-$ p_{\mathrm{T}} $ top quarks in e/$\mu$+jets final states at 8 TeV
Abstract: The differential top-antitop quark production cross section is measured for top quarks with high transverse momentum in pp collisions at a center-of-mass energy of 8 TeV. The data sample was collected with the CMS detector during 2012 and corresponds to an integrated luminosity of 19.7 $\pm$ 0.5 fb$^{-1}$. The measurement is performed for events in e/$\mu$+jets final states where the hadronically decaying top quark is reconstructed as a single large-radius jet and identified as a top candidate using jet substructure techniques. The integrated cross section is measured at particle-level within a fiducial region resembling the detector-level selection as well as at parton-level. At particle-level, the cross section is measured to be $\sigma_{\mathrm { t\bar{t}} } = $ 1.28 $\pm$ 0.09 (stat+syst) $\pm$ 0.10 (PDF) $\pm$ 0.09 (Q$^2$) $\pm$ 0.03 (lumi) pb for $p_{\mathrm T} >$ 400 GeV. At parton-level, it is measured to be $\sigma_{\mathrm { t\bar{t} } } =$ 1.44 $\pm$ 0.10 (stat+syst) $\pm$ 0.13 (PDF) $\pm$ 0.15 (Q$^2$) $\pm$ 0.04 (lumi) pb, 14% lower than the estimate from $\mathrm{t \bar{t}}$ events simulated using POWHEG. The hadronic top-jet candidate $p_{\mathrm T}$ distribution is corrected for detector effects to extract normalized differential cross sections at particle- and parton-level.
CMS Publications
Compact Muon Solenoid
LHC, CERN