  A search for WW production from double-parton scattering processes using
same-charge electron-muon and dimuon events is reported, based on proton-proton
collision data collected at a center-of-mass energy of 13 TeV. The analyzed
data set corresponds to an integrated luminosity of 77.4 fb$^{-1}$, collected
using the CMS detector at the LHC in 2016 and 2017. Multivariate classifiers
are used to discriminate between the signal and the dominant background
processes. A maximum likelihood fit is performed to extract the signal cross
section. This leads to the first evidence for WW production via double-parton
scattering, with a significance of 3.9 standard deviations. The measured
inclusive cross section is 1.41 $\pm$ 0.28 (stat) $\pm$ 0.28 (syst) pb.
