Top Quark Pair Production Cross Section and Forward-Backward Asymmetry at the Tevatron

TL;DR

This paper reports precise measurements of top quark pair production cross sections and forward-backward asymmetries at the Tevatron, comparing results from CDF and DØ experiments to theoretical predictions and exploring potential signs of new physics.

Contribution

It provides new combined measurements of top quark pair production cross sections and forward-backward asymmetries using the full datasets from CDF and DØ, with improved precision and analysis methods.

Findings

Top cross section measurements are consistent with theoretical predictions.

Forward-backward asymmetry measurements are presented at parton level and detector level.

Results suggest no significant deviation from the Standard Model.

Abstract

We present recent results on top quark pair production cross section and forward-backward asymmetry at the Tevatron. Three new cross section measurements from CDF and one new measurement from DO are presented that utilize the full dataset available. A new DO top cross section combination gives a ttbar production cross section of sigma_ttbar = 7.83 + 0.46-0.45 (stat) + 0.64-0.53 (syst) +-0.48 (lumi). The new CDF cross section combination for ttbar production is found to be 7.0 +- 0.3 (stat) +- 0.4 (syst) +- 0.4 (lumi) pb giving a total uncertainty of 9%, very close to the that of the current best theoretical predictions. It is important to measure the top cross section in as many different channels as possible and investigate their compatibility. This is useful as new physics might show up differently in the different channels. Thus any significant discrepancy could be a sign of new physics. Three new measurements of the forward-backward asymmetry are also presented. The two CDF measurements unfold the observed asymmetry back to parton level in order to directly compare the values obtained with theoretical predictions. The DO measurement is not unfolded and therefore does not depend on the specific method used for unfolding.