Measurement of Higgs Boson Production Cross Sections in the Diphoton Channel - with the full ATLAS Run-2 Data and Constraints on Anomalous Higgs Boson Interactions

This thesis presents the measurement of the Higgs boson cross section in the diphoton decay channel. The thesis details the calibration of electron and photon energies in ATLAS, in particular the measurement of the presampler energy scale and the estimation of its systematic uncertainty.