Evidence for Higgs boson Yukawa couplings in the $H\rightarrow\tau\tau$ decay mode with the ATLAS detector

Results of a search for H ! decays are presented, based on the full set of protonprotoncollision data recorded by the ATLAS experiment at the LHC during 2011 and 2012.The data correspond to integrated luminosities of 4.5 fb1 and 20.3 fb1 at centre-of-massenergies ofps = 7 TeV andps = 8 TeV respectively. All combinations of leptonic( ! `¯ with ` = e; ) and hadronic ( ! hadrons ) tau decays are considered. Anexcess of events over the expected background from other Standard Model processes isfound with an observed (expected) significance of 4.5 (3.5) standard deviations. This excessprovides evidence for the direct coupling of the recently discovered Higgs boson with massmH=125 GeV to fermions. The measured signal strength, normalised to the Standard Modelexpectation, of = 1:42 +0:440:38 is consistent with the predicted Yukawa coupling strength inthe Standard Model.