Search for the Decay of the Higgs Boson to Charm Quarks with the ATLAS Experiment

A direct search for the standard model Higgs boson decaying to a pair of charm quarks is presented. Associated production of the Higgs and Z bosons, in the decay mode ZH → ℓ⁺ℓ⁻cc̅ is studied. A data set with an integrated luminosity of 36.1fb⁻¹ of pp collisions at √s = 13 TeV recorded by the ATLAS experiment at the LHC is used. The H → cc̅ signature is identified using charm-tagging algorithms. The observed (expected) upper limit on σ(pp → ZH) × B(H → cc̅ ) is 2.7 (3.9 +2.1-1.1) pb at the 95% confidencelevel for a Higgs boson mass of 125 GeV, while the standard model value is 26 fb.