"Cross section" of "Measurement of inclusive and differential cross sections for single top quark production in association with a W boson in proton-proton collisions at $\sqrt{s}$ = 13 TeV"

Observed and theoretical cross sections. In the observed, the first uncertainty is statistical, the second is the systematic, and the third the luminosity. In the theoretical, the first uncertainty is due to scale variations, the second due to the choice of PDF. The theoretical cross section has been computed at approximate next-to-next-to-leading order (aNNLO) assuming a top quark mass of 172.5 GeV.