Search for Higgs boson production at high transverse momentum in the WW decay channel in proton-proton collisions at √s=13 TeV

A bstract A search for Higgs boson (H) production at high transverse momentum ( p T ) in the WW decay channel is presented. The analysis uses proton-proton collisions at √s=13 s = 13 TeV recorded by the CMS experiment in 2016–2018, corresponding to an integrated luminosity of 138 fb − 1 . The visible decay products of the Higgs boson are reconstructed as a single large-radius jet with one isolated lepton or none (1 ℓ and 0 ℓ , respectively; ℓ = e, μ ). The H-candidate jets are identified using an advanced transformer-based algorithm and are calibrated with the Lund jet plane reweighting technique. The 1 ℓ channel is further split into gluon fusion, vector boson fusion, and associated production with hadronically decaying vector boson categories, while the 0 ℓ channel considers all production processes inclusively. The measured cross section times the H → WW branching fraction relative to the standard model expectation is μ =-0.19-0.46+0.48 μ = − 0.19 − 0.46 + 0.48 , indicating no evidence of a signal above the background. This measurement represents the first dedicated study of highly Lorentz-boosted H → WW decays, complementing earlier searches for high- p T Higgs boson in other decay channels.