Search for a new resonance decaying into two spin-0 bosons in a final state with two photons and two bottom quarks in proton-proton collisions at s = 13 TeV

A bstract A search for a new boson X is presented using CERN LHC proton-proton collision data collected by the CMS experiment at s s = 13 TeV in 2016–2018, and corresponding to an integrated luminosity of 138 fb − 1. The resonance X decays into either a pair of Higgs bosons HH of mass 125 GeV or an H and a new spin-0 boson Y. One H subsequently decays to a pair of photons, and the second H or Y, to a pair of bottom quarks. The explored mass ranges of X are 260–1000 GeV and 300–1000 GeV, for decays to HH and to HY, respectively, with the Y mass range being 90–800 GeV. For a spin-0 X hypothesis, the 95% confidence level upper limit on the product of its production cross section and decay branching fraction is observed to be within 0. 90–0. 04 fb, depending on the masses of X and Y. The largest deviation from the background-only hypothesis with a local (global) significance of 3. 8 (below 2. 8) standard deviations is observed for X and Y masses of 650 and 90 GeV, respectively. The limits are interpreted using several models of new physics.