Search for charged Higgs bosons produced in association with a top quark and decaying via H^± → τν using pp collision data recorded at √s = 13 TeV by the ATLAS detector

Charged Higgs bosons produced in association with a single top quark and decaying via H^±→τν are searched for with the ATLAS experiment at the LHC, using proton-proton collision data at √s=13 TeV corresponding to an integrated luminosity of 3.2 fb⁻¹. The final state is characterised by the presence of a hadronic τ decay andmissing transverse momentum, as well as a hadronically decaying top quark, resulting in the absence of high-transverse-momentum electrons and muons. The data are found to be consistent with the expected background from Standard Model processes. A statistical analysis leads to 95% confidence-level upper limits on the production cross section times branching fraction, σ(pp→[b]tH^±)×BR(H^±→τν), between 1.9 pb and 15 fb, for charged Higgs boson masses ranging from 200 to 2000 GeV. The exclusion limits for this search surpass those obtained with the proton-proton collision data recorded at √s=8 TeV.