Searches for new phenomena in high-mass diphoton final states with the ATLAS experiment at the LHC are presented. The analysis is based on pp collision data corresponding to an integrated luminosity of 36.7 fb−1at a centre-of-mass energy s=13 TeV recorded in 2015 and 2016. Searches are performed for resonances with spin 0, as predicted by theories with an extended Higgs sector, and for resonances with spin 2, using a warped extra-dimension model as a benchmark model, as well as for non-resonant signals, assuming a large extra-dimension scenario. No significant deviation from the Standard Model is observed. Upper limits are placed on the production cross section times branching ratio to two photons as a function of the resonance mass. In addition, lower limits are set on the ultraviolet cutoff scale in the large extra-dimensions model.

Aaboud, M., Aad, G., Abbott, B., Abdinov, O., Abeloos, B., Abidi, S.H., et al. (2017). Search for new phenomena in high-mass diphoton final states using 37 fbâ 1of protonâ proton collisions collected at s=13 TeV with the ATLAS detector. PHYSICS LETTERS. SECTION B, 775, 105-125 [10.1016/j.physletb.2017.10.039].

Search for new phenomena in high-mass diphoton final states using 37 fb−1of proton–proton collisions collected at s=13 TeV with the ATLAS detector

Ceradini F.;Di Micco B.;Di Nardo R.;Orestano D.;Petrucci F.;