NLO QCD+EW predictions for V+jets including off-shell vector-boson decays and multijet merging

TL;DR

This paper provides advanced NLO QCD and electroweak predictions for off-shell vector boson production with jets at the 13 TeV LHC, including a new method for multijet merging to improve theoretical accuracy.

Contribution

It introduces an approximate method for incorporating NLO EW corrections into multijet merging frameworks, enhancing simulation precision for V+jets processes.

Findings

Electroweak corrections are crucial at the TeV scale due to large Sudakov logarithms.

The new method improves the reliability of predictions involving up to two jets.

Predictions show strong sensitivity of key observables to multijet emissions.

Abstract

We present next-to-leading order (NLO) predictions including QCD and electroweak (EW) corrections for the production and decay of off-shell electroweak vector bosons in association with up to two jets at the 13 TeV LHC. All possible dilepton final states with zero, one or two charged leptons that can arise from off-shell W and Z bosons or photons are considered. All predictions are obtained using the automated implementation of NLO QCD+EW corrections in the OpenLoops matrix-element generator combined with the Munich and Sherpa Monte Carlo frameworks. Electroweak corrections play an especially important role in the context of BSM searches, due to the presence of large EW Sudakov logarithms at the TeV scale. In this kinematic regime, important observables such as the jet transverse momentum or the total transverse energy are strongly sensitive to multijet emissions. As a result, fixed-order NLO QCD+EW predictions are plagued by huge QCD corrections and poor theoretical precision. To remedy this problem we present an approximate method that allows for a simple and reliable implementation of NLO EW corrections in the MEPS@NLO multijet merging framework. Using this general approach we present an inclusive simulation of vector-boson production in association with jets that guarantees NLO QCD+EW accuracy in all phase space regions involving up to two resolved jets.