Parton Shower Effects on W and Z Production via Vector Boson Fusion at NLO QCD

TL;DR

This paper implements electroweak Zjj and Wjj production via vector boson fusion at NLO QCD within the POWHEG framework, analyzing the impact of different parton shower algorithms on relevant observables.

Contribution

It provides the first implementation of VBF Zjj and Wjj production with leptonic decays at NLO QCD in POWHEG, including a comparison of multiple parton shower models.

Findings

Observables related to the third jet are sensitive to the parton shower used.

Different shower algorithms produce notable variations in jet-related observables.

The implementation aids in background modeling for Higgs searches and studies of anomalous couplings.

Abstract

We present the implementation of electroweak Zjj and Wjj production via vector boson fusion with fully leptonic decays at NLO QCD in the POWHEG framework. These processes represent an important background to Higgs searches in vector boson fusion, but they also can be seen as signal processes to study anomalous triple vector boson couplings as well as the impact of a central jet veto. Observables related to the third jet are sensitive to the parton shower which is used, a fact which is demonstrated by a comparison between PYTHIA, the standard angular-ordered HERWIG++ shower and the new p_T-ordered Dipole Shower in HERWIG++.