Update of the Combination of Higgs Boson Searches in pp Collisions at sqrt(s) = 7 TeV with the ATLAS Experiment at the LHC

The combination of searches for the Higgs boson by the ATLAS experiment with the first ~1 fb−1 of data taken in 2011 at the LHC is updated. The H → ZZ(∗) → l+l−l+l− and H → W W (∗) → l+ ν l− ν searches are complemented with additional datasets corresponding to 1.1 and 0.6 fb−1 of integrated luminosity and now correspond to 2–2.3 fb−1and 1.7 fb−1 respectively. The H → WW(∗) → l+νl−ν channel analysis is improved and two channels searching for the Higgs boson decaying to tau leptons are now included. An excess of events is observed in the low mass range. Its significance is at most approximately 2 standard devi- ations above the expected SM background. The Higgs boson mass ranges from 146 GeV to 230 GeV, 256 GeV to 282 GeV and 296 GeV to 459 GeV are excluded at the 95% CL, while the expected Higgs boson mass exclusion in the absence of a signal ranges from 131 GeV to 450 GeV. The result of these searches is also interpreted in the framework of a Standard Model with the addition of a heavy sequential fourth generation of fermions. In this model Higgs boson masses above 119 GeV and up to 593 GeV are excluded at the 95%CL.