Search for new resonances in high-mass diphoton final states using proton-proton collision data collected with the ATLAS detector

A search for new resonances decaying to two photons is performed, using 139 $fb^{-1}$ collision data at $\sqrt{s}$=3TeV collected by the ATLAS detector at the LHC. A spin-0 signal predicted by theories with extended Higgs sector and a spin-2 graviton excitation using a warped extra-dimension benchmark model are searched for. No significant deviation from the Standard Model is observed. Upper limits are set on the production cross-section times branching ratio asa function of the resonance mass and width.