A measurement of total production cross sections of the Higgs boson in proton--proton collisions is presented in the $H\rightarrow\tau\tau$ decay channel. The analysis is performed using 36.1\,\rm{fb}^{-1} of data recorded by the ATLAS experiment at the Large Hadron Collider at a center-of-mass energy of \sqrt{s}=13\,\rm{TeV}. All combinations of leptonic ($\tau \rightarrow \ell \nu \bar{\nu}$ with $\ell = e, \mu$) and hadronic (\tau \to \rm{hadrons}~ \nu) tau decays are considered. The $H\rightarrow\tau\tau$ signal over the expected background from other Standard Model processes is established with an observed (expected) significance of 4.4 (4.1) standard deviations. Combined with results using data taken at 7 and 8 TeV centre-of-mass energies, the observed (expected) significance amounts to 6.4 (5.4) standard deviations and constitutes an observation of $H\rightarrow\tau\tau$ decays by the ATLAS experiment. Using the data taken at \sqrt{s}=13\,\rm{TeV}, the total cross section in the $H\rightarrow\tau\tau$ decay channel is measured to be 3.71\pm 0.59\,\text{(stat.)}\,^{+0.87}_{-0.74}\,\text{(syst.)}\,\rm{pb}, for a Higgs boson of mass 125 GeV. Total cross sections in the $H\rightarrow\tau\tau$ decay channel are measured separately for vector boson fusion production and gluon--gluon fusion production to be 0.28 \pm 0.09\,\text{(stat.)}\,^{+0.11}_{-0.09}\,\text{(syst.)}\,\rm{pb} and 3.0 \pm 1.0\,\text{(stat.)}\,^{+1.6}_{-1.2}\,\text{(syst.)}\,\rm{pb}, respectively. All measurements are in agreement with Standard Model expectations.

Log in to your administrator account to edit.