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 36.1 fb⁻¹ of pp collisions at √s = 13TeV 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) x ℬ(H → cc̅) is 2.7 (3.9{_{-1.1}^{+2.1}}) pb at the 95% confidence level for a Higgs boson mass of 125 GeV, while the standard model value is 26 fb.