CMS-PAS-TOP-15-011 | ||
Comparisons of theory predictions for the $\mathrm{ t \bar{t} }$ process with data from pp collisions at $\sqrt{s} =$ 8 TeV | ||
CMS Collaboration | ||
December 2015 | ||
Abstract: Studies are presented comparing $\mathrm{ t \bar{t} } $ differential distribution data collected with the CMS detector at $\sqrt{s}=$ 8 TeV to state-of-the-art theoretical predictions. The predictions are accurate to next-to-leading order quantum chromodynamics and interfaced with the PYTHIA 8 and HERWIG++ event generators. The predictions of these simulation tools and a next-to-next-to-leading order calculation are compared to unfolded data distributions. All deviations of the theory predictions from the data remain inside the envelope considered for factorization and renormalization scale variations. | ||
Links: CDS record (PDF) ; inSPIRE record ; Rivet record ; CADI line (restricted) ; |
Summary |
Studies are presented comparing $\mathrm{ t \bar{t} } $ differential distribution data, obtained with the CMS detector at $\sqrt{s} =$ 8 TeV in the lepton+jets and dilepton channels, to state-of-the-art matrix element Monte Carlo event generators at next-to-leading order in QCD, used in conjunction with the parton showers PYTHIA 8 and HERWIG++. The predictions of these improved simulation tools are compared to unfolded data distributions. A RIVET module, providing all the results discussed in this manuscript, is made publicly available. The NLO theory predictions do not always improve the agreement with data with respect to the LO ones, but from this study we can conclude that any deviation observed with respect to the central value of the NLO theory predictions is covered by the uncertainty assigned to the choice of the renormalization and factorization scales at the matrix element level. |
Compact Muon Solenoid LHC, CERN |