Stress-testing the VBF approximation in multijet final states

TL;DR

This paper evaluates the accuracy of the VBF approximation in Higgs plus three jets production at NLO QCD, revealing conditions under which the approximation holds and highlighting the impact of different kinematic cuts.

Contribution

It provides the first detailed comparison of full and approximate calculations of Higgs plus three jets production beyond VBF cuts, assessing the approximation's validity.

Findings

Rapidity gap between jets ensures good VBF approximation

Invariant mass cut alone is insufficient for approximation accuracy

QCD corrections largely stem from Higgs-Strahlungs topologies

Abstract

We consider electro-weak Higgs plus three jets production at NLO QCD beyond strict VBF acceptance cuts. We investigate, for the first time, how accurate the VBF approximation is in these regions and within perturbative uncertainties, by a detailed comparison of full and approximate calculations. We find that a rapidity gap between the tagging jets guarantees a good approximation, while an invariant mass cut alone is not sufficient, which needs to be confronted with experimental choices. We also find that a significant part of the QCD corrections can be attributed to Higgs-Strahlungs-type topologies.