Search for Anomalous Higgs Boson Couplings in the Production of WH via Vector Boson Scattering

The measured properties of the Higgs boson are in good agreement with the Standard Model (SM) prediction. All the couplings are consistent with the SM, but they are measured as absolute values. In particular, the coupling modifiers for the W and Z boson (κ_W and κ_Z in the “κ” framework) are allowed to have either a positive or negative sign in previous CMS fits. In this analysis we use the production of a W and Higgs boson (WH) via vector boson scattering (VBS) to probe the relative sign of the vector boson couplings, i.e. the κ_W/κ_Z=λ_WZ parameter that is predicted to be 1 in the SM. We specifically search for VBS WH production with negative κ_W and positive κ_Z, which is equivalent to negative κ_Z and positive κ_W (negative λ_WZ) at tree level. The final state considered includes one lepton from the W candidate, a large-cone jet tagged as a Higgs candidate and two jets for the VBS signature. The analysis uses data from proton-proton collisions at √s = 13 TeV, collected by the CMS detector during 2016, 2017 and 2018, corresponding to 138 fb^-1. Negative values of λ_WZ are expected to be excluded.