Measurements of Higgs boson production via gluon–gluon fusion and vector-boson fusion using H → WW∗ → νν decays in pp collisions with the ATLAS detector and their effective field theory interpretations

Higgs boson production cross-sections via gluon– gluon fusion and vector-boson fusion in proton–proton collisions are measured in the H → W W∗ → νν decay channel. The Large Hadron Collider delivered proton–proton collisions at a centre-of-mass energy of 13 TeV between 2015 and 2018, which were recorded by the ATLAS detector, corresponding to an integrated luminosity of 140 fb−1. The total cross-sections for Higgs boson production by gluon–gluon fusion and vector-boson fusion times the H → W W∗ branching ratio are measured to be 12.4+1.3 −1.2 pb and 0.79+0.18 −0.16 pb, respectively, in agreement with the Standard Model predictions. Higgs boson production is further characterised through measurements of Simplified Template CrossSections in a total of fifteen kinematic fiducial regions. A new scheme of kinematic fiducial regions has been introduced to enhance the sensitivity to CP-violating effects in Higgs boson interactions. Both schemes are used to constrain CPeven and CP-odd dimension-six operators in the Standard Model effective field theory.