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

We calculate a comprehensive set of spin correlations and differential distributions in top-quark pair production and decay to dilepton final states. Our calculation is performed in the Narrow Width Approximation. 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.

Automated summary

This study provides a comprehensive analysis of spin correlations and differential distributions in top-quark pair production and decay to dilepton final states at next-to-next-to leading order in QCD. Good agreement between NNLO QCD predictions and data is observed, demonstrating the possibility of high-precision comparisons. The impact of top quark definition subtleties on production at absolute threshold is highlighted.