Search for a vector-like quark decaying to a top quark and a W boson

A search is presented for single production of vector-like quarks (VLQs) in proton-proton collisions at $\sqrt{s} = 13~\mathrm{TeV}$ recorded with the CMS experiment at the LHC. The analyzed data sample corresponds to an integrated luminosity of $35.9~\mathrm{fb}^{-1}$. The analysis focuses on the VLQ decay into a top quark and a W boson with one muon or electron in the final state. The mass of the VLQ candidates is reconstructed from identified b quark jets, as well as highly Lorentz boosted hadronic W boson and top quark decays. No significant deviation from the standard model background expectation is observed. Exclusion limits at $95\%$ confidence level are set on the production cross section times branching fraction as a function of the VLQ mass, which range from $0.3~\mathrm{pb}$ for a VLQ mass of $700~\mathrm{GeV}$ down to $0.03~\mathrm{pb}$ for $1800~\mathrm{GeV}$.