Sensitivity study for a heavy gauge boson W' in the decay channel with a tau lepton and a neutrino at the High-Luminosity LHC

A sensitivity study for the discovery or exclusion of a heavy vector boson W' in the final state with a tau lepton and a neutrino is presented. Event samples are simulated for the Phase-2 CMS detector at the High-Luminosity LHC (corresponding to an integrated luminosity of $3~\mathrm{ab}^{-1}$), using the parameterized detector simulation program DELPHES. A signal would appear as an excess of events with high transverse mass of the hadronic tau and missing transverse momentum, compared to the standard model background. With the high integrated luminosity during Phase-2, a W' boson with SM-like couplings could be observed with a significance exceeding five standard deviations with a mass up to 6.0 TeV. In case of no observation, the results are interpreted as lower limits on the mass of the W' boson in the context of the sequential standard model. In addition, variations in the coupling strength are studied, and a model-independent cross section limit is provided.