Determination of the top-quark mass from top-quark pair events with the matrix element method at next-to-leading order: Potential and prospects

Abstract

In 2004 the matrix element method was used in a pioneering work by the Tevatron experiment D0 to determine the top-quark mass from a handful of events. Since then the method has been matured into a powerful analysis tool. While the first applications were restricted to leading-order accuracy, in the meantime also the extension to next-to-leading order (NLO) accuracy has been studied. In this article we explore the potential of the matrix element method at NLO to determine the top-quark mass using events with pair-produced top quarks. We simulate a toy experiment by generating unweighted events with a fixed input mass and apply the matrix element method to construct an estimator for the top-quark mass. Two different setups are investigated: unweighted events obtained from the fixed-order cross section at NLO accuracy as well as events obtained using POWHEG matched to a parton shower. The latter lead to a more realistic simulation and allow to study the impact of higher-order corrections as well as the robustness of the approach. We find that the matrix element method in NLO accuracy leads to a significant reduction of the theoretical uncertainties compared to leading order. In view of the high luminosity phase of the LHC, this observation is especially relevant in analyses which are no longer dominated by statistical uncertainties.

arXiv commentTwo references added, particle labels adjusted to improve readability, error bars added in ratio plots, minor changes to the text

References in corpus (33)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX
• A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• A General Algorithm for Calculating Jet Cross Sections in NLO QCD
• The total top quark pair production cross-section at hadron colliders through O(alpha_S^4)
• A Positive-Weight Next-to-Leading-Order Monte Carlo for Heavy Flavour Hadroproduction
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• Top-pair production at hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation
• The Dipole Formalism for Next-to-Leading Order QCD Calculations with Massive Partons
• Higher Order Corrections to Jet Cross Sections in Hadron Colliders
• Hadronic top-quark pair production with NNLL threshold resummation
• High-precision differential predictions for top-quark pairs at the LHC
• Top quark pair production and decay at hadron colliders
• NLO QCD corrections to top quark pair production and decay at hadron colliders
• Threshold Resummation for Top-Pair Hadroproduction to Next-to-Next-to-Leading Log
• Top-quark pair hadroproduction at next-to-next-to-leading order in QCD
• Electroweak effects in top-quark pair production at Hadron Colliders
• Top-quark pair production at the LHC: Fully differential QCD predictions at NNLO
• NNLO QCD predictions for fully-differential top-quark pair production at the Tevatron
• Weak interaction corrections to hadronic top quark pair production
• Threshold expansion of the gg(qq) -> QQ+X cross section at O(alpha_s^4)
• Weak corrections to gluon-induced top-antitop hadro-production
• The impact of the photon PDF and electroweak corrections on $t\bar{t}$ distributions
• Resummation for (boosted) top-quark pair production at NNLO+NNLL' in QCD
• Extending the Matrix Element Method beyond the Born approximation: Calculating event weights at next-to-leading order accuracy
• Soft-gluon resummation for boosted top-quark production at hadron colliders
• Boosted top production: factorization and resummation for single-particle inclusive distributions
• One-Loop Helicity Amplitudes for ttbar Production at Hadron Colliders
• The Matrix Element Method at next-to-leading order QCD for hadronic collisions: Single top-quark production at the LHC as an example application
• Matrix Element Method at NLO for (anti-)${\mathbf{k}}_{\mathbf{t}}$-jet algorithms