Higgs-boson plus Dijets: Higher-Order Matching for High-Energy Predictions

TL;DR

This paper introduces an improved matching framework for the High Energy Jets (HEJ) formalism, enhancing high-energy predictions for Higgs plus dijet processes at the LHC by simplifying calculations and demonstrating perturbative stability.

Contribution

An improved HEJ matching framework that simplifies high-multiplicity calculations while maintaining accuracy, applied to Higgs plus dijet production in the VBF region.

Findings

Higher-multiplicity matching has a small impact on predictions.

The improved HEJ matches well with NLO results.

Perturbative stability is achieved within HEJ.

Abstract

Several important processes and analyses at the LHC are sensitive to higher-order perturbative corrections beyond what can currently be calculated at fixed order. The formalism of High Energy Jets (HEJ) calculates the corrections systematically enhanced for a large ratio of the centre-of-mass energy to the transverse momentum of the observed jets. These effects are relevant in the analysis of e.g. Higgs-boson production in association with dijets within the cuts devised to enhance the contribution from Vector Boson Fusion (VBF). HEJ obtains an all-order approximation, based on logarithmic corrections which are matched to fixed-order results in the cases where these can be readily evaluated. In this paper we present an improved framework for the matching utilised in HEJ, which for merging of tree-level results is mathematically equivalent to the one used so far. However, by starting from events generated at fixed order and supplementing these with the all-order summation, it is computationally simpler to obtain matching to calculations of high multiplicity. We demonstrate that the impact of the higher-multiplicity matching on predictions is small for the gluon-fusion (GF) contribution of Higgs-boson production in association with dijets in the VBF-region, so perturbative stability against high-multiplicity matching has been achieved within HEJ. We match the improved HEJ prediction to the inclusive next-to-leading order (NLO) cross section and compare to pure NLO in the h->photon photon channel with standard VBF cuts.