Top-Quark Physics at the LHC

TL;DR

This paper presents high-precision measurements of the top-quark mass at the LHC, discusses calibration of the Monte Carlo mass parameter, and introduces advanced calculations for top-quark processes relevant for future colliders and top-Yukawa coupling extraction.

Contribution

It provides the first matched exclusive calculations for top-quark production at future lepton colliders, and improves the theoretical understanding of top-quark mass determination and top-Yukawa coupling measurement.

Findings

Precise top-quark mass determined at NNLO in QCD.

Calibration method for Monte Carlo top-quark mass parameter.

Next-to-leading order calculations for off-shell top-pair production.

Abstract

We report on the precision determination of the top-quark mass to next-to-next-to-leading order in QCD in well-defined renormalization schemes using data from the Large Hadron Collider for single-top and top-quark pair production. We also discuss the calibration of the so-called Monte Carlo top-quark mass parameter which is determined from a comparison to events with top-quark decay products. The implications of the measured value of the top-quark mass for conclusions about the stability of the electroweak vacuum state of our Universe are illustrated. At future lepton colliders, we provide for the first time matched exclusive calculations valid both at the top threshold and in the continuum, also fully differentially. In addition, we calculate fully off-shell top-pair production (also with an associated Higgs boson) at next-to-leading order in QCD, which allows to extract the top-Yukawa coupling with an unprecedented precision.