Top quark and leptonic charge asymmetries for the Tevatron and LHC

TL;DR

This paper calculates top quark and leptonic charge asymmetries at the Tevatron and LHC to NLO in QCD, including electroweak corrections, comparing with experimental data and exploring their measurability.

Contribution

It provides the first comprehensive NLO QCD and electroweak predictions for top and leptonic charge asymmetries at hadron colliders, including kinematic cuts and experimental comparisons.

Findings

Asymmetries are smaller for leptons but measurable.

Results agree with some experimental measurements.

Electroweak corrections impact asymmetry predictions.

Abstract

We compute, for $t \bar t$ production at the LHC and at the Tevatron, several charge asymmetries to NLO QCD, including also the electromagnetic and weak-interaction corrections. We calculate these asymmetries both inclusively and with additional kinematic cuts and compare our results, where possible, with recent experimental results and with SM predictions. The $t \bar t$ asymmetries induce also corresponding asymmetries for the charged leptons from semileptonic top-quark decay. Although these asymmetries are, in the SM, smaller than the corresponding ones for top quarks, they are expected to be measurable quite precisely. In fact, measurement of a lepton asymmetry in $\ell$ + jets events was reported by the D$\emptyset$ and CDF experiments. We analyze and compute to NLO in the gauge couplings leptonic charge asymmetries for dileptonic and semileptonic $\ttbar$ events, with and without acceptance cuts, at the Tevatron and the LHC.