Abstract
The inclusive Higgs boson production cross-section is measured in the di-photon and the ZZ∗→4ℓ decay channels using 31.4 and 29.0 fb−1 of pp collision data respectively, collected with the ATLAS detector at a centre-of-mass energy of s√=13.6 TeV. To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the channel's detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are σfid,γγ=76+14−13 fb, and σfid,4ℓ=2.80±0.74 fb, in agreement with the corresponding Standard Model predictions of 67.6±3.7 fb and 3.67±0.19 fb. Assuming Standard Model acceptances and branching fractions for the two channels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of σ(pp→H)=67+12−11 pb and 46±12 pb at 13.6 TeV from the di-photon and ZZ∗→4ℓ measurements respectively. The two measurements are combined into a total cross-section measurement of σ(pp→H)=58.2±8.7 pb, to be compared with the Standard Model prediction of σ(pp→H)SM=59.9±2.6 pb.