  Inclusive and normalised differential cross sections measurements are
presented for the production of single top quarks in association with a W
boson, in proton-proton collisions at a centre-of-mass energy of 13 TeV. Events
containing one muon and one electron in the final state are analysed. For the
inclusive measurement, a multivariate discriminant, exploiting the kinematic
properties of the events, is used to separate the signal from the dominant
t$\bar{\mathrm{t}}$ background. For the differential measurements, a fiducial
region is defined according to the detector acceptance, and the requirement of
exactly one b-tagged jet. The resulting distributions are unfolded to
particle-level and compared with predictions at next-to-leading order in
perturbative QCD. Within current uncertainties, all predictions agree with the
data.
