NNLO QCD corrections to leptonic observables in top-quark pair production and decay

TL;DR

This paper presents the first comprehensive NNLO QCD calculations of spin correlations and differential distributions in top-quark pair production and decay, enabling high-precision comparisons with experimental data.

Contribution

It provides a complete NNLO QCD analysis of top-quark pair production and decay observables, including spin correlations and differential distributions, at both inclusive and fiducial levels.

Findings

Good agreement between NNLO predictions and data.

High-precision fixed-order calculations are feasible at fiducial level.

Subtleties in top quark definitions significantly affect threshold behavior.

Abstract

We calculate a comprehensive set of spin correlations and differential distributions in top-quark pair production and decay to dilepton final states. This is the first time such a complete study is performed at next-to-next-to leading order in QCD. Both inclusive and fiducial distributions are presented and analyzed. Good agreement between NNLO QCD predictions and data is found. We demonstrate that it is possible to perform high-precision comparisons of fixed-order calculations with fiducial-level data. Subtleties of the top quark definition are raised and clarified. Some of those are found to have a very significant impact on top-quark pair production at absolute threshold.