Probing anomalous top-Higgs couplings at the HL-LHC via H → WW* decay channels

We study the prospects of probing the anomalous tHq (q = u, c) couplings via SS2L or 3L signatures at the High Luminosity (HL-LHC) run of the 14 TeV CERN collider. We focus on signals of the tH associated production followed by the decay modes t -> bl(+)nu(l) and H -> WW*, and t (t) over bar production followed by the decay modes t -> bl(+)nu(l) and (t) over bar -> H (-> WW*)(q) over bar, where l = e, mu. Based on two types of H -> WW* decay topologies, one assuming the semileptonic decay mode H -> WW* -> l(+)nu jj and the other the fully leptonic decay mode H -> WW* -> l(+)nu l(-)(nu) over bar, we perform a full simulation for signals and backgrounds. It is shown that, at the future HL-LHC, the branching ratio Br(t -> uh) (Br(t -> ch)) can be probed to 1.17 (1.56) x 10(-3) for the same-sign di-lepton channel, and to 7.1 x 10(-4) (1.39 x 10(-3)) for the 3L channel at 3 sigma sensitivity.