Differential cross-section measurements of Higgs boson production in the H RIGHTWARDS ARROW τ+τ- decay channel in pp collisions at SQUARE ROOTs = 13 TeV with the ATLAS detector

Abstract

Differential measurements of Higgs boson production in the τ -lepton-pair decaychannel are presented in the gluon fusion, vector-boson fusion (VBF), V H and t-tH associatedproduction modes, with particular focus on the VBF production mode. The data used toperform the measurements correspond to 140 fb-1 of proton-proton collisions collected by theATLAS experiment at the LHC. Two methods are used to perform the measurements: theSimplified Template Cross-Section (STXS) approach and an Unfolded Fiducial Differentialmeasurement considering only the VBF phase space. For the STXS measurement, events arecategorized by their production mode and kinematic properties such as the Higgs boson'stransverse momentum (pHT), the number of jets produced in association with the Higgs boson,or the invariant mass of the two leading jets (mjj ). For the VBF production mode, theratio of the measured cross-section to the Standard Model prediction for mjj > 1.5TeV andpHT> 200 GeV (pHT< 200 GeV) is 1.29+0.39-0.34 (0.12+0.34-0.33). This is the first VBF measurement forthe higher-pHTcriteria, and the most precise for the lower-pHTcriteria. The fiducial cross-sectionmeasurements, which only consider the kinematic properties of the event, are performed asfunctions of variables characterizing the VBF topology, such as the signed Δϕjj between thetwo leading jets. The measurements have a precision of 30%-50% and agree well with theStandard Model predictions. These results are interpreted in the SMEFT framework, andplace the strongest constraints to date on the CP-odd Wilson coefficient cH ~W .