Search for exotic decays of the Higgs Boson using photons with the CMS experiment

In multiple beyond the standard model (SM) scenarios, the 125 GeV Higgs boson (H) can decay to light pseudoscalars (a), each of which decay into two photons, resulting in a four photon final state. We present a search for exotic decays of the SM Higgs boson in the four photon final state using 132 fb − 1 of proton-proton collision data collected by the CMS experiment at a center-of-mass energy of 13 TeV. This analysis probes pseudoscalars that range in mass from 15 GeV to 60 GeV and decay into photons that are reconstructed as resolved objects in the CMS electromagnetic calorimeter. Although the branching fraction for a → 𝛾𝛾 is subdominant, the low backgrounds in the four photon final state make it important to study. These new results, the first in the four photon final state from CMS, set limits on the product of the production cross-section of the SM Higgs boson times the branching ratio of H → 𝑎𝑎 → 𝛾𝛾𝛾𝛾 , as a function of pseudoscalar mass.