Towards an update of the ILD ZHH analysis

¹ Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
² SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California, United States
³ Department of Physics, Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
⁴ International Center for Elementary Particle Physics (ICEPP), The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033

^* *Speaker E-mail: bryan.bliewert@desy.de, caterina@slac.stanford.edu, dntounis@stanford.edu, jenny.list@desy.de, julie.munch.torndal@desy.de, tian@icepp.s.u-tokyo.ac.jp

Published online: 18 December 2024

Abstract

The double Higgs-strahlungs process e⁺e⁻ → 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.