UCLA

This dissertation presents a CMS search strategy for Higgs boson pair production in the gluon-gluon fusion process in the single-lepton resolved final state of the HH → bbWW channel. The study is based on simulated proton-proton collisions representative of CMS Run 3 conditions at √ s = 13.6 TeV. Events are selected in the single-lepton channel (exactly one electron or muon) and categorized in the resolved topology by jet multiplicity. A systematic comparison between likelihood-ratio- and neural-network-based discriminants is performed; the neural network provides superior separation and is used to set the expected 95% CL upper limit on the signal strength, µ = 19.3, for the single-lepton resolved topology using simulated 2022+2023 samples. The statistical interpretation includes only the integrated-luminosity and statistical uncertainties. In parallel, new low-pT lepton triggers developed within CMS and commissioned in 2024 are expected to increase acceptance for HH → bbWW events in subsequent Run 3 analyses. These developments demonstrate improved sensitivity relative to Run 2 and highlight the methodological progress achieved in preparation for the full Run 3 HH → bbWW analysis.