Search for the Standard Model Higgs boson produced in association with a vector boson and decaying into a tau pair in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector

A search for the Standard Model Higgs boson produced in association with a vector boson with the decay $H\to \tau \tau$ is presented. The data correspond to 20.3 fb${}^{-1}$ of integrated luminosity from proton-proton collisions at $\sqrt{s}=8$ TeV recorded by the ATLAS experiment at the LHC during 2012. The data agree with the background expectation, and 95% confidence-level upper limits are placed on the cross section of this process. The observed (expected) limit, expressed in terms of the signal strength $\mu = \sigma/\sigma_{$\mathrm{S}\mathrm{M}$}$for$m_$\mathrm{H}$ = 125 GeV$,is$\mu <$ 5.6 (3.7). The measured value of the signal strength is $\mu =2.3\pm 1.6$.