Search for vector-boson resonances decaying to a top quark and bottom quark in the lepton plus jets final state in Collisions at with the ATLAS detector

A search for new charged massive gauge bosons, ${W}^{\prime }$, is performed with the ATLAS detector at the LHC. Data were collected in proton–proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV and correspond to an integrated luminosity of $36.1\phantom{\rule{0.25em}{0ex}}\text{fb}{}^{-1}$. This analysis searches for ${W}^{\prime }$ bosons in the ${W}^{\prime }\to t\overline{b}$ decay channel in final states with an electron or muon plus jets. The search covers resonance masses between 0.5 and 5.0 TeV and considers right-handed ${W}^{\prime }$ bosons. No significant deviation from the Standard Model (SM) expectation is observed and upper limits are set on the ${W}^{\prime }\to t\overline{b}$ cross section times branching ratio and the ${W}^{\prime }$ boson effective couplings as a function of the ${W}^{\prime }$ boson mass. For right-handed ${W}^{\prime }$ bosons with coupling to the SM particles equal to the SM weak coupling constant, masses below 3.15 TeV are excluded at the 95% confidence level. This search is also combined with a previously published ATLAS result for ${W}^{\prime }\to t\overline{b}$ in the fully hadronic final state. Using the combined searches, right-handed ${W}^{\prime }$ bosons with masses below 3.25 TeV are excluded at the 95% confidence level.