Measurement of the Higgs boson production cross section in association with a vector boson and decaying into $WW^\ast$ with the ATLAS detector at $\sqrt{s} = 13$ TeV

A measurement of the total Higgs boson production cross sections via associated $WH$ and $ZH$ production using $H\to WW^{*}\to \ell\nu\ell\nu$ and $H\to WW^{*} \to \ell\nu jj$ decays is presented. Results for combined $WH$ and $ZH$ production are also presented. The analysis uses proton-proton events delivered by the Large Hadron Collider at a centre-of-mass energy of 13 TeV and recorded by the ATLAS detector between 2015 and 2018. The data correspond to an integrated luminosity of 139 fb$^{-1}$. The products of the $H\to WW^{*}$ branching fraction times the $WH$ and $ZH$ cross sections are measured to be $0.13^{+0.08}_{-0.07}$(stat.)$^{+0.05}_{-0.04}$(syst.) pb and $0.31^{+0.09}_{-0.08}$(stat.)$\pm0.03$(syst.) pb, respectively, in agreement with the Standard Model predictions.