Search for high-mass resonances in final states with a tau lepton and missing transverse momentum with the ATLAS detector

A search for high-mass resonances decaying to tau lepton and a neutrino using proton–proton collisions at a center-of-mass energy of $\sqrt{s}=$13 TeV is presented. The full Run-2 dataset corresponding to an integrated luminosity of 139fb$^{−1}$ recorded by the ATLAS experiment in the years 2015-2018 has been analyzed. The tau lepton is reconstructed in hadronic decay modes. No excess of events above the Standard Model background is observed and upper exclusion limits are set on the $W'\to\tau\nu$ production cross section. Heavy $W'$ bosons with masses up to 5.0 TeV are excluded at the 95% confidence level, assuming that they have the same couplings as the Standard Model W boson.