Measurements of the Higgs boson production cross section via Vector Boson Fusion and associated $WH$ production in the $WW^{\ast} \to \ell\nu\ell\nu$ decay mode with the ATLAS detector at $\sqrt{s}$ = 13 TeV

Measurements of the Higgs boson production cross section via Vector Boson Fusion (VBF) and associated $WH$ production using $H \rightarrow WW^{\ast} \rightarrow \ell\nu\ell\nu$ decays are presented. The analyses use events produced in proton-proton collisions collected with the ATLAS detector at the LHC in 2015 and 2016. The data correspond to an integrated luminosity of $5.8\,\mathrm{fb}^{-1}$ recorded at $\sqrt{s} = 13\,\mathrm{TeV}$. The total production cross sections are measured to be $\sigma_{\mathrm{VBF}}\cdot \mathcal{B}_{H \rightarrow WW^{\ast}} = 1.4^{+0.9}_{-0.7}\; \mathrm{pb}$ and $\sigma_{WH}\cdot \mathcal{B}_{H \rightarrow WW^{\ast}} = 0.9 ^{+1.3}_{-1.2}\; \mathrm{pb}$. The ratios of the measured value to the expected value of the total production cross section times branching fraction for VBF and $WH$ production, $\mu_{\rm VBF}$ and $\mu_{WH}$, correspond to $\mu_{\rm VBF} = 1.7^{+1.1}_{-0.9}$ and $\mu_{WH} = 3.2 ^{+4.4}_{-4.2}$, assuming a Higgs boson mass of $m_{H} = 125\,\mathrm{GeV}$. Since the measurements are statistically limited, 95\% confidence-level upper limits on the cross section times branching fraction of $3.0\; \mathrm{pb}$ and $3.3\; \mathrm{pb}$ are set for VBF and $WH$ production, respectively.