Search for high-mass exclusive diphoton production withtagged protons
CMS Collaboration
A search for high-mass exclusive diphoton production via photon-photon fusion withtagged protons is presented. The analysis utilizes 102.7 fb−1of data collected by theCMS and TOTEM Precision Proton Spectrometer in the 2016, 2017, and 2018 LHCruns. Events are selected that have two photons with high transverse momenta thatare back-to-back in azimuth and with a large diphoton invariant mass. To removethe dominant backgrounds, tagged final state protons from the event are required tomatch the kinematics of the final state photons. Only events having opposite-side protons within an asymmetric fractional momentum loss between 0.035 and 0.15 (0.18)for the detectors on the negative (positive) side of CMS are considered. One exclusivediphoton candidate is observed for an expected background of 1.1 events. Limits at95% confidence level are derived on the four-photon anomalous coupling parametersfor |ζ1| < 7.3 × 10−14 GeV−4, |ζ2| < 1.5 × 10−13 GeV−4 using an effective field theory.Additionally, axion-like particles are excluded in the mass range of 500 to 2000 GeV.
https://cds.cern.ch/record/2810862/files/EXO-21-007-pas.pdf
