Search for a heavy resonance decaying into a top quark and a W boson in the lepton+jets final state at 13 TeV

A search for a heavy resonance decaying into a top quark and a W boson in proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$ is presented. The data analyzed were recorded with the CMS detector at the LHC and correspond to an integrated luminosity of $137~\mathrm{fb}^{-1}$. The search is performed in the lepton+jets final state, where the lepton is either an electron or muon. The top quark is reconstructed with a single jet and the W boson from its decay into a charged lepton and a neutrino. A top quark tagging technique based on a jet clustering with variable distance parameter and inherent jet grooming is used to identify jets from the collimated top quark decay. An excited bottom quark $\mathrm{b}^\ast$ model is used as a benchmark. A combination with an analysis in the all-hadronic final state is performed. At $95\%$ confidence level, $\mathrm{b}^\ast$ masses up to 2.95, 3.03 and 3.22 TeV are excluded for left-handed, right-handed and vector-like couplings, respectively.