Measurements of Higgs boson production via gluon–gluon fusion and vector-boson fusion using H→WW∗→ℓνℓνH→WW∗→ℓνℓν 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→WW∗→ℓνℓνH→WW∗→ℓνℓν decay channel. The Large Hadron Collider delivered proton–proton collisions at a centre-of-mass energy of 13 TeV13TeV between 2015 and 2018, which were recorded by the ATLAS detector, corresponding to an integrated luminosity of 140 fb−1.140fb−1. The total cross-sections for Higgs boson production by gluon–gluon fusion and vector-boson fusion times the H→WW∗H→WW∗ branching ratio are measured to be 12.4−1.2+1.3 pb12.4−1.2+1.3​pb and 0.79−0.16+0.18 pb,0.79−0.16+0.18​pb, respectively, in agreement with the Standard Model predictions. Higgs boson production is further characterised through measurements of Simplified Template Cross-Sections 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 CP-even and CP-odd dimension-six operators in the Standard Model effective field theory.