Theoretical results for top quark production

TL;DR

This paper compares various methods for calculating top quark production, demonstrating that soft-gluon resummation closely matches exact NNLO results and validating approximate distributions against experimental data.

Contribution

It provides a detailed comparison of higher-order calculation approaches, highlighting the accuracy of soft-gluon resummation for top quark production at collider energies.

Findings

Soft-gluon resummation results are nearly identical to exact NNLO cross sections.

Approximate NNLO distributions agree well with LHC measurements.

The study informs improvements in theoretical predictions for top quark processes.

Abstract

I discuss and compare several approaches to higher-order calculations of top quark production. I study the relative effectiveness of the approaches in approximating the exact NNLO results for the top-pair total cross section and highlight the theoretical and numerical differences between them. I show that the results from my soft-gluon resummation method are nearly identical to the exact NNLO cross section at all LHC and Tevatron energies. This agreement has important consequences for the validity of existing approximate NNLO differential distributions, for further refinements of the predictions, and for applications to other processes such as single-top production. I also compare approximate NNLO top quark transverse momentum and rapidity distributions with recent LHC measurements.