Measurement of the integrated and differential $t \bar t$ production cross sections for high-$p_t$ top quarks in $pp$ collisions at $\sqrt s =$ 8 TeV

The cross section for pair production of top quarks (tt¯) with high transverse momenta is measured in pp collisions, collected with the CMS detector at the LHC with s=8 TeV in data corresponding to an integrated luminosity of 19.7 fb-1. The measurement is performed using lepton+jets events, where one top quark decays semileptonically, while the second top quark decays to a hadronic final state. The hadronic decay is reconstructed as a single, large-radius jet, and identified as a top quark candidate using jet substructure techniques. The integrated cross section and the differential cross sections as a function of top quark pT and rapidity are measured at particle level within a fiducial region related to the detector-level requirements and at parton level. The particle-level integrated cross section is found to be σtt¯=0.499±0.035(stat+syst)±0.095(theo)±0.013(lumi) pb for top quark pT>400 GeV. The parton-level measurement is σtt¯=1.44±0.10(stat+syst)±0.29(theo)±0.04(lumi) pb. The integrated and differential cross section results are compared to predictions from several event generators.

Note:

Replaced with published version. Added the journal reference and DOI. Figures and tables, including supplemental figures, can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/TOP-14-012/

p p: colliding beams
top: pair production
top: decay
p p: scattering
transverse momentum: high
final state: hadronic
differential cross section: measured
channel cross section: measured
CERN LHC Coll
numerical calculations: Monte Carlo

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