Search for two boosted Higgs bosons decaying to four bottom quarks with CMS

We present a search for Higgs pair production in the boosted 4b final state using proton–proton collision data collected by the CMS detector at √s = 13 TeV. Events are selected with two large-radius jets consistent with Higgs decays to bb̄, identified using the transformer-based GloParT b-tagging algorithm. A multivariate classifier is trained to separate signal from the dominant QCD multijet and tt̄ backgrounds. The analysis uses a partial Run-3 dataset (2022-23) corresponding to an integrated luminosity of 62 fb⁻¹. No significant excess is observed relative to the Standard Model expectation. An observed (expected) 95% confidence-level upper limit on the non-resonant Higgs boson pair production cross section is set at 8.1 (11) times the Standard Model prediction. Constraints on the Higgs boson self-coupling yield an observed (expected) 2σ interval of [−11.0, 19.2] ([−10.3, 18.4]), and the modifier of the Higgs–vector-boson coupling is constrained to [0.30, 1.74] ([0.47, 1.58]). These results represent the most sensitive CMS search for HH → bb̄bb̄ in the boosted topology to date, enabled by improved jet tagging and signal discrimination techniques.