Observation of an excess of events in the Higgs boson search in ATLAS

A preliminary combined search for the Standard Model Higgs boson with the ATLAS experiment at the LHC is presented. The pp collisions datasets correspond to an integrated luminosity of up to 4.9 fb-1 collected at sqrt(s) = 7 TeV in 2011, and up to 5.9 fb-1 collected at sqrt(s) = 8 TeV in 2012. Searches for H to gamma gamma, H to ZZ(*), H to WW(*), H to bbar and H to tau tau have been performed on the 2011 data, while H to gamma gamma and H to ZZ(*) to 4l have been updated using both 2011 and 2012 data. The Standard Model Higgs boson has been excluded at 95% confidence level for masses in the range of 110 to 122.6 GeV and 129.7 to 558 GeV. An excess of events has been observed for a Higgs boson mass hypothesis near 126.5 GeV with a local significance of 5.0 sigma.