Top quark pair production at NNLO in the quark-antiquark channel

TL;DR

This paper derives and implements NNLO corrections for top quark pair production in the quark-antiquark channel, providing precise differential distributions and asymmetry predictions consistent with experimental data.

Contribution

It completes the NNLO corrections for top pair production in the quark-antiquark channel by deriving two-parton contributions using antenna subtraction and implementing them in a parton-level event generator.

Findings

NNLO corrections improve the accuracy of top pair production predictions.

Results agree well with Tevatron measurements of the forward-backward asymmetry.

Provides detailed differential distributions for LHC and Tevatron.

Abstract

We present the derivation of the NNLO two-parton final state contributions to top pair production in the quark-antiquark channel proportionnal to the leading colour factor $N_c^2$. Together with the three and four-parton NNLO contributions presented in a previous publication, this enables us to complete the phenomenologically most important NNLO corrections to top pair hadro-production in this channel. We derive this two-parton contribution using the massive extension of the NNLO antenna subtraction formalism and implement those corrections in a parton-level event generator providing full kinematical information on all final state particles. In addition, we also derive the heavy quark contributions proportional to $N_h$. Combining the new leading-colour and heavy quark contributions together with the light quark contributions derived previously, we present NNLO differential distributions for LHC and Tevatron. We also compute the differential top quark forward-backward asymmetry at Tevatron and find that our results are in good agreement with the measurements by the D0 collaboration.