MEASUREMENT OF THE ASSOCIATED PRODUCTION OF A HIGGS BOSON DECAYING INTO b-QUARKS WITH A VECTOR BOSON AT HIGH TRANSVERSE MOMENTUM WITH THE ATLAS DETECTOR

The observation of the decay of the Higgs boson to a b (b) over bar pair in 2018 provided a confirmation of the Yukawa interaction and the first measurement of a Yukawa coupling to down-type quarks. The experimental challenges that the H -> b (b) over bar decay entails at hadron colliders can be addressed by studying the associated Higgs boson production with a vector boson V decaying leptonically. Following the observation, the main focus is now the study of the Higgs boson production cross section as a function of its transverse momentum (pT). These measurements are well motivated by a wide range of Beyond the Standard Model (BSM) theories predicting an enhancement of V H(H -> b (b) over bar) events at high transverse momentum with respect to the SM expectations. At such high energy regimes, the Higgs boson is highly Lorentz-boosted and the H ! bb (b) over bar decay is reconstructed in the detector as a single object with a two-prong substructure, using novel techniques. The paper will illustrate the measurement of VH(H -> b (b) over bar) in the boosted regime performed inclusively, as well as in bins of the vector boson transverse momentum, for p(T)(V) is an element of [250, 400) GeV and p(T)(V) is an element of [400,infinity) GeV. Their interpretation using the Effective Field Theory (EFT) framework will also be discussed. The results are based on the full LHC Run 2 dataset collected by the ATLAS experiment, corresponding to an integrated luminosity of 139 fb(-1).