Measurement of the Higgs boson inclusive and differential fiducial production cross sections in the diphoton decay channel with pp collisions at $sqrt{s}=$ 13 TeV with the CMS detector

The measurements of the inclusive and differential fiducial cross sections of the Higgs boson decaying to a pair of photons are presented. The analysis is performed using proton-proton collisions collected with the CMS detector at the LHC at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of $138\,\text{fb}^{-1}$. The inclusive fiducial cross section is measured to be $\sigma_{\text{fid}}=73.40_{-5.3}^{+5.4}\text{(stat)}_{-2.2}^{+2.4}\text{(syst)}\,\text{fb}$, in agreement with the standard model expectation of $75.44\pm4.1\,\text{fb}$. The measurements are also performed in fiducial regions targeting different production modes and as a function of several observables describing the diphoton system, the number of additional jets present in the events, and event-level observables. No significant deviations from the standard model expectations are observed.