Search for the Higgs boson in the di-tau channel using the ATLAS detector

A search for the Standard Model (SM) Higgs boson decaying into a pair of τ leptons is reported. The analysis, exploiting each of the lep-lep, lep-had and had-had final states, is based on data samples of proton-proton collisions collected by the ATLAS experiment at the LHC and corresponding to integrated luminosities of 4.6 ifb and 13.0 ifb at centre-of-mass energies of sqrt{s} 7 TeV and 8 TeV, respectively. The observed (expected) upper limit at 95% CL on the cross-section times the branching ratio for SM H→τ+τ− is found to be 1.9 (1.2) times the SM prediction for a Higgs boson with mass mH=125 GeV. For this mass, the observed (expected) deviation from the background-only hypothesis corresponds to a local significance of 1.1 (1.7) standard deviations.