Measurements of Higgs boson properties in the diphoton decay channel using 80 fb$^{-1}$ of $pp$ collision data at $\sqrt s$ = 13 TeV with the ATLAS detector

This note reports measurements of Higgs boson properties in the two-photon final state using 79.8 fb$^{-1}$ of data recorded at $\sqrt{s}=13$ TeV by the ATLAS experiment at the Large Hadron Collider. The cross sections of Higgs boson production through gluon--gluon fusion, vector-boson fusion, and in association with a vector boson or a top-quark pair are measured. Measurements of the Higgs boson production divided further into kinematic regions, called simplified template cross sections, are also reported. Additionally, the cross section for the production of the Higgs boson decaying to two isolated photons is measured in a fiducial phase space designed to closely match the ATLAS detector acceptance, and is found to be 60.4 $\pm$ 6.1 (stat.) $\pm$ 6.0 (exp.) $\pm$ 0.3 (theo.) fb, in agreement with the Standard Model prediction of 63.5 $\pm$ 3.3 fb. Finally, the fiducial cross section is measured differentially in bins of several kinematic observables with sensitivity to properties of the Higgs boson. Among these, the number of $b$-jets produced in association with the Higgs boson is measured to probe Higgs production in association with heavy flavor hadrons. No significant deviations between the observed data and the Standard Model prediction are observed.