Improving NLO QCD event generators with high-energy EW corrections

TL;DR

This paper introduces a new reweighting method to incorporate high-energy electroweak corrections into NLO QCD event generators, enhancing the accuracy of simulations for hadroproduction processes.

Contribution

A novel reweighting approach that combines electroweak Sudakov logarithms with NLO+PS predictions, implemented in MadGraph5_aMC@NLO for automated event generation.

Findings

Improved accuracy in simulating top-quark pair production.

Enhanced modeling of Higgs boson associated production.

Validated method with phenomenological results for multiple processes.

Abstract

In this work we present a new approach for the combination of electroweak (EW) corrections at high energies, the so-called EW Sudakov logarithms (EWSL), and next-to-leading-order QCD predictions matched to parton-shower simulations (NLO+PS). Our approach is based on a reweighting procedure of NLO+PS events. In particular, both events with and without an extra hard emission from matrix elements are consistently reweighted via the inclusion of the corresponding EWSL contribution. We describe the technical details and the implementation in the MadGraph5_aMC@NLO framework. Via a completely automated procedure, events at this new level of accuracy can be obtained for a vast class of hadroproduction processes. As a byproduct we provide results for phenomenologically relevant physical distributions from top-quark pair and Higgs boson associated production ($t\overline{t}H$) and from the associated production of three $Z$ gauge bosons ($ZZZ$).