Monte Carlo studies of the jet activity in Higgs + 2 jet events

TL;DR

This study analyzes Higgs production with two jets at the LHC, focusing on distinguishing gluon-fusion and vector-boson-fusion mechanisms through jet correlations and central-jet activity. It combines matrix-element calculations (ALPGEN) with parton-shower/hadronization (HERWIG) in the $m_t\to\infty$ limit to assess higher-order effects on the azimuthal angle between tagging jets and on extra-jet rapidity distributions. The results show that the characteristic dip in the azimuthal distribution survives higher-order effects, though softened by showering, and that central-jet activity patterns align with expectations from the underlying color structure, enabling effective discrimination between ggF and VBF. The work also highlights LO-generation cut sensitivities and suggests using Sudakov-resummed or CKKW-style approaches for more robust predictions, guiding future refinements toward more precise Higgs coupling measurements.

Abstract

Tree-level studies have shown in the past that kinematical correlations between the two jets in Higgs+2-jet events are direct probes of the Higgs couplings, e.g. of their CP nature. In this paper we explore the impact of higher-order corrections on the azimuthal angle correlation of the two leading jets and on the rapidity distribution of extra jets. Our study includes matrix-element and shower MC effects, for the two leading sources of Higgs plus two jet events at the CERN LHC, namely vector-boson and gluon fusion. We show that the discriminating features present in the previous leading-order matrix element studies survive.