Tumasyan, A.Adam, W.Andrejkovic, J. W.Bergauer, T.Chatterjee, S.Dragicevic, M.Gürpınar Güler, EmineGüler, YalçınThe CMS Collaboration2022-01-302022-01-3020211029-8479https://doi.org/10.1007/JHEP11(2021)111https://hdl.handle.net/20.500.13091/1730A measurement of the cross section of the associated production of a single top quark and a W boson in final states with a muon or electron and jets in proton-proton collisions at root s = 13 TeV is presented. The data correspond to an integrated luminosity of 36 fb(-1) collected with the CMS detector at the CERN LHC in 2016. A boosted decision tree is used to separate the tW signal from the dominant t (t) over bar background, whilst the subleading W+jets and multijet backgrounds are constrained using data-based estimates. This result is the first observation of the tW process in final states containing a muon or electron and jets, with a significance exceeding 5 standard deviations. The cross section is determined to be 89 +/- 4 (stat) +/- 12 (syst) pb, consistent with the standard model.eninfo:eu-repo/semantics/openAccessHadron-Hadron Scattering (Experiments)Top PhysicsArticle10.1007/JHEP11(2021)1112-s2.0-85119607780