Measurement of the differential cross section for top quark pair production in pp collisions at sqrt(s) = 8 TeV

TL;DR

This paper measures the normalized differential cross section for top quark pair production at 8 TeV using CMS data, comparing results with QCD predictions and finding no significant deviations from the Standard Model.

Contribution

It provides the first detailed measurement of differential cross sections for top quark pairs at 8 TeV, testing QCD predictions with high precision.

Findings

Results agree with perturbative QCD up to NNLO

No significant deviations from Standard Model observed

Provides detailed kinematic distributions of top quark pairs

Abstract

The normalized differential cross section for top quark pair (tt-bar) production is measured in pp collisions at a centre-of-mass energy of 8 TeV at the CERN LHC using the CMS detector in data corresponding to an integrated luminosity of 19.7 inverse femtobarns. The measurements are performed in the lepton + jets (e/mu + jets) and in the dilepton (e+e-, mu+mu-, and e+-mu-+) decay channels. The tt-bar cross section is measured as a function of the kinematic properties of the charged leptons, the jets associated to b quarks, the top quarks, and the tt-bar system. The data are compared with several predictions from perturbative quantum chromodynamics up to approximate next-to-next-to-leading-order precision. No significant deviations are observed relative to the standard model predictions.