Measurement of the differential cross sections for top quark pair production as a function of kinematic event variables in pp collisions at sqrt(s) = 7 and 8 TeV

TL;DR

This paper reports measurements of normalized differential cross sections for top quark pair production at 7 and 8 TeV, comparing data with standard model predictions and finding good agreement.

Contribution

First measurement of differential cross sections for top quark pairs as a function of multiple kinematic variables at LHC energies.

Findings

No significant deviations from standard model predictions.

Results agree with several event simulation generators.

Provides data for refining top quark production models.

Abstract

Measurements are reported of the normalized differential cross sections for top quark pair production with respect to four kinematic event variables: the missing transverse energy; the scalar sum of the jet transverse momentum (pT); the scalar sum of the pT of all objects in the event; and the pT of leptonically decaying W bosons from top quark decays. The data sample, collected using the CMS detector at the LHC, consists of 5.0 inverse femtobarns of proton-proton collisions at sqrt(s) = 7 TeV and 19.7 inverse femtobarns at sqrt(s) = 8 TeV. Top quark pair events containing one electron or muon are selected. The results are presented after correcting for detector effects to allow direct comparison with theoretical predictions. No significant deviations from the predictions of several standard model event simulation generators are observed.