Evidence for vector-boson fusion production of $H\rightarrow WW^\ast \rightarrow \ell\nu\ell\nu$

Evidence for the vector-boson fusion (VBF) production of the Higgs boson in its $WW^\ast$ decay channel in the dilepton final state is reported. The analysis was performed on 7 and 8~TeV pp collisions recorded by the ATLAS detector with an integrated luminosity of $25\, \mathrm{fb}^{-1}$. One of the main improvements over the previous result is the adoption of multivariate technique for an improved sensitivity to the VBF signal. For a Higgs boson mass of 125.36 GeV, the best-fit value for the ratio of the signal strength for gluon fusion (ggF) and VBF production, $\mu_{math{VBF}}/\mu_{\mathrm{ggF}}$, is measured to be $1.26\,^{+0.61}_{-0.45} \mathrm{(stat.)}\,^{+0.50}_{-0.26} \mathrm{(syst.)}$. The observed significance of the VBF production is 3.2 standard deviations; the expected is 2.7 standard deviations. This marks the final run~1 measurement in this channel; the inclusion of the upcoming run~2 data will improve the precision further and take us to the next step towards the Higgs boson precision era.