Search for the Standard Model Higgs boson at ATLAS

A search for the Standard Model Higgs boson has been performed with the ATLAS experiment at LHC using data corresponding to integrated luminosities from 1.04 fb-1 to 4.9 fb-1 of pp collisions collected at sqrt{s}=7 TeV in 2011. The Higgs boson mass ranges 112.9-115.5 GeV, 131-238 GeV and 251-466 GeV are excluded at the 95% confidence level, while the range 124-519 GeV is expected to be excluded in the absence of a signal. An excess of events is observed around the mass of ~126 GeV with a local significance of 3.5 standard deviations. The global probability for the background to produce such a fluctuation anywhere in the explored Higgs boson mass range 110-600 GeV is estimated to be ~1.4% or, equivalently 2.2 standard deviations.