Towards an update of the ILD ZHH analysis

TL;DR

This paper discusses updating the projections for measuring the Higgs self-coupling via the ZHH process at the ILC, incorporating recent improvements in reconstruction tools to refine the analysis for future collider studies.

Contribution

It provides an updated analysis of the ZHH process at the ILC, integrating recent reconstruction improvements to enhance measurement projections.

Findings

Updated ZHH analysis projections for ILC

Improved reconstruction tools increase measurement sensitivity

Enhanced understanding of Higgs self-coupling measurement potential

Abstract

The double Higgs-strahlungs process $e^+e^- \rightarrow ZHH$ allows to access the Higgs self-coupling at center-of-mass energies above $450$ GeV. Its cross-section exhibits a very different behavior as a function of the value of the self-coupling than fusion-type processes like gluon-gluon fusion at LHC (and future hadron colliders) and $WW$ / $ZZ$ fusion at higher energy lepton colliders. Therefore it adds unique information to the picture, in particular should the value of the Higgs self-coupling differ from its Standard Model prediction. The last full evaluation of the potential of the ILC to measure this process is more than ten years old, and since then many of the reconstruction tools have received very significant improvements. This contribution presents the ongoing work in the ILD collaboration to update the ZHH projections for the next European Particle Physics Strategy Update.