Simultaneous inference of the Higgs boson width and couplings using the ATLAS off-shell Higgs boson production measurement in the H* → ZZ decay channel

This poster presents a study using the ATLAS measurement of the Higgs boson width published with the full Run-2 dataset at √s = 13 TeV (140 fb⁻¹), based on the off-shell production measurement in the H → ZZ decay channel. In this study, we re-evaluate the hypotheses on the Higgs couplings used by ATLAS to measure the total Higgs boson width using the κ-framework. The measured Higgs boson width and its associated uncertainty are evaluated under different assumptions for the coupling of the Higgs boson to gluons κg and to vector bosons κV. The study combines measurements in the H* → ZZ → 4ℓ and H* → ZZ → 2ℓ2ν decay channels and reinterprets them as indirect constraints on the Higgs boson branching ratio to BSM states using the H → ZZ channel only. Full profile likelihood results are presented using the neural simulation-based inference technique.