Search for the Standard Model Higgs Boson Decay to μ⁺μ⁻ with the ATLAS Detector

A search is reported for Higgs boson decay to μ⁺μ⁻ using data with an integrated luminosity of 24.8 fb⁻¹ collected with the ATLAS detector in pp collisions at √s̅ = 7 and 8 TeV at the CERN Large Hadron Collider. The observed dimuon invariant mass distribution is consistent with the Standard Model background-only hypothesis in the 120-150 GeV search range. For a Higgs boson with a mass of 125.5 GeV, the observed (expected) upper limit at the 95% confidence level is 7.0 (7.2) times the Standard Model expectation. This corresponds to an upper limit on the branching ratio BR(H → μ⁺μ⁻) of 1.5 x10⁻³.