The Matrix Element Method at next-to-leading order QCD for hadronic collisions: Single top-quark production at the LHC as an example application

TL;DR

This paper extends the Matrix Element Method to include next-to-leading-order QCD corrections for hadronic processes, demonstrating its application to single top-quark production at the LHC and highlighting improved accuracy in top-quark mass measurements.

Contribution

The authors develop a general algorithm for applying the Matrix Element Method at NLO QCD to hadronic collisions, specifically for single top-quark production, and showcase its practical implementation.

Findings

NLO corrections significantly affect the MEM results.

Inclusion of NLO is essential for reliable uncertainty estimates.

MEM at NLO provides a viable alternative for top-quark mass measurement.

Abstract

In a recent work the authors have presented a general algorithm to extend the Matrix Element Method (MEM) to the hadronic production of coloured partons taking into account next-to-leading-order (NLO) corrections in quantum chromodynamics (QCD). In this article, the general algorithm is applied to the production of single top quarks at the LHC. In particular, the generation of unweighted events following the NLO predictions is presented. Treating these events as the result of a toy experiment we illustrate the first application of the Matrix Element Method at NLO QCD for hadronic jet production. As a concrete example, we study the determination of the top-quark mass. We show that the inclusion of the NLO corrections can lead to sizeable effects compared to the Matrix Element Method relying on leading-order predictions only and that the incorporation of the NLO corrections is mandatory to obtain reliable estimates of the theoretical uncertainties. In addition, we find that measuring the top-quark mass using the MEM in single top-quark production offers an interesting alternative to mass measurements in top-quark pair production.