Search for exclusive diphoton production with intact protons in pp collisions at the LHC

When compared to the Standard Model, enhancements to the four-photon coupling production rate are predicted by many models of new physics. The strongest sensitivity to study this process at the Large Hadron Collider in proton-proton collisions requires measuring the original intact protons in the final state. Data is studied from the CMS experiment at $\sqrt{s} = 13 \TeV$ utilizing the Precision Proton Spectrometer for proton tagging. Results are shown from dataset corresponding from the 2016 data-taking period and the LHC Run II data-taking period. No events are observed above the background prediction. The first limits are placed on the four-photon anomalous coupling and the strongest limits to data are placed on axion-like particle production in the mass range of 500 \GeV $<$ $\textrm{m}_{\textrm{ALP}}$ $<$ 2000 \GeV.