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Compact Muon Solenoid
LHC, CERN

CMS-PAS-HIG-25-004
Constraints on the Higgs boson total decay width using signal-background interference in the diphoton final state with proton-proton collisions at $ \sqrt{s}= $ 13 TeV
Abstract: The standard model Higgs boson with a mass of 125 GeV is predicted to have a decay width $ \Gamma_{\mathrm{H}} $ of 4.1 MeV. Direct $ \Gamma_{\mathrm{H}} $ measurements using on-shell Higgs boson production are limited by the experimental resolution which is of the order of 1 GeV in the diphoton and four-lepton final states. This note presents, for the first time at the LHC, a constraint on $ \Gamma_{\mathrm{H}} $ from the diphoton invariant mass distribution in the on-shell Higgs boson decay, using the interference between the amplitudes of the $ gg \rightarrow H \rightarrow \gamma \gamma $ process and one of the continuum QCD $ gg\to \gamma\gamma $ process. This study was carried out using the proton-proton collision data at a center-of-mass energy of 13 TeV, collected by the CMS experiment during LHC Run 2 and corresponding to an integrated luminosity of 138 fb$ ^{\mathrm{-1}} $. The observed (expected) limit on the Higgs boson width is $ \Gamma_{\mathrm{H}} < $ 92 (138) MeV at the 95% confidence level.
CMS Publications
Compact Muon Solenoid
LHC, CERN