Measurement of the WW cross section pp collisions at sqrt(s)=13 TeV

A measurement of the $\mathrm{W}^{+}\mathrm{W}^{-}$ cross section in $\mathrm{pp}$ collisions at $13\,\mathrm{TeV}$ is presented. The data were collected with the CMS detector at the LHC in 2015, and correspond to an integrated luminosity of $2.3 \pm 0.1\,\mathrm{fb}^{-1}$. The measurement is performed by selecting events with one electron and one muon of opposite charge, accompanied by large missing transverse energy. The $\mathrm{W}^{+}\mathrm{W}^{-}$ cross section is measured to be $115.3\pm 5.8\mathrm{(stat)}\pm 5.7\mathrm{(exp)}\pm 6.4\mathrm{(theo)}\pm 3.6\mathrm{(lum)}\,\mathrm{pb}$, consistent with the standard model prediction.