NLO corrections to electroweak and QCD production of W+W+ plus two jets in the POWHEGBOX

TL;DR

This work implements the NLO-QCD calculation for electroweak W^+W^+jj production in vector-boson fusion within the POWHEG BOX, enabling robust matching to parton-shower programs and providing a complete SM description alongside the existing QCD-induced W^+W^+jj implementation. The authors detail the virtual and real-emission contributions, the Denner–Dittmaier tensor reduction for numerical stability, and the FKS-based infrared subtraction within POWHEG BOX, as well as a dedicated tagging scheme for color-singlet exchange. Phenomenologically, VBF cuts suppress QCD backgrounds, making EW production the dominant mechanism in the studied region, while parton-shower effects mostly preserve distributions but can influence central-jet veto–related observables, particularly for the third jet. The publicly available implementation facilitates accurate NLO QCD + parton-shower predictions for W^+W^+jj final states and supports realistic SM background modeling for new physics searches involving same-sign leptons.

Abstract

We present the matching of the next-to-leading order QCD calculation for W+W+jj production via vector-boson fusion in hadronic collisions to parton-shower Monte-Carlo programs according to the POWHEG method. Our implementation complements existing code for QCD-induced W+W+jj production in the POWHEGBOX package, thereby providing a platform for the complete Standard Model production of W+W+jj events via QCD and electroweak interactions. The impact of parton-shower effects is discussed for various distributions and found to be small in most cases. However, few observables, that are relevant for analyses using a central jet veto, are modified significantly when they are interfaced to a parton shower program.