Combination of cross-section measurements of associated production of a single top quark and a W boson at $\sqrt{s} = 8~\mathrm{TeV}$ with the ATLAS and CMS experiments

A combination of cross-section measurements for the associated production of a top quark and a W boson in proton-proton collisions at $\sqrt{s}=8~\mathrm{TeV}$ by the ATLAS and CMS experiments is presented. The two measurements are based on integrated luminosities of $20.3~\mathrm{fb}^{-1}$ and $12.2~\mathrm{fb}^{-1}$, respectively. The combined production cross-section of a single top quark and a W~boson is determined as $23.1 \pm 1.1~(\mathrm{stat.}) \pm 3.3~(\mathrm{syst.}) \pm 0.8~(\mathrm{lumi.})~\mathrm{pb} = 23.1 \pm 3.6~\mathrm{pb}$, in agreement with the NLO+NNLL expectation.