Search for resonances decaying into photon pairs in 139 fb$^{-1}$ of $pp$ collisions at $\sqrt{s} =$ 13 TeV with the ATLAS detector

TL;DR

This paper reports a search for new particle resonances decaying into photon pairs using 139 fb$^{-1}$ of 13 TeV proton-proton collision data from the ATLAS detector, finding no evidence of such resonances.

Contribution

First search for diphoton resonances in 139 fb$^{-1}$ of 13 TeV data with ATLAS, setting limits on new resonance production cross-sections.

Findings

No significant excess observed over Standard Model predictions.

Upper limits set on resonance production cross-section times branching ratio.

Constraints placed on models with extended Higgs sectors and warped extra dimensions.

Abstract

Searches for new resonances in the diphoton final state, with spin 0 as predicted by theories with an extended Higgs sector and with spin 2 using a warped extra-dimension benchmark model, are presented using 139 fb$^{-1}$ of $\sqrt{s} = $ 13 TeV $pp$ collision data collected by the ATLAS experiment at the LHC. No significant deviation from the Standard Model is observed and upper limits are placed on the production cross-section times branching ratio to two photons as a function of the resonance mass.