Evidence for the standard model production of a Z boson with a single top quark in pp collisions at $\sqrt{s}=13~\mathrm{TeV}$

Evidence for the standard model production of a Z boson in association with a single top quark is presented. The study uses a data sample of proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$ recorded in 2016 by the CMS experiment, corresponding to an integrated luminosity of $35.9~\mathrm{fb}^{-1}$. Final states with three leptons (electrons or muons) and at least two jets are investigated. The corresponding measured tZq measured cross section is $\sigma (\mathrm{pp}\rightarrow\mathrm{tZq}\rightarrow\mathrm{Wb}\ell^+\ell^-\mathrm{q}) = 123^{+44}_{-39}$ fb, where $\ell$ stands for electrons, muons, and taus, with an observed (expected) significance of 3.7 (3.1) standard deviations. $$\textit{This document has been revised with respect to the version dated Sep 19, 2017.}$$