Probing anomalous top-Higgs couplings at the HL-LHC via $H\to W{W}^{\ast }$ decay channels

Abstract

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 $t\to b{\ell }^{+}{\nu }_{\ell }$ and $H\to W{W}^{\ast }$, and $t\bar{t}$ production followed by the decay modes $t\to b{\ell }^{+}{\nu }_{\ell }$ and $\bar{t}\to H(\to W{W}^{\ast })\bar{q}$, where $\ell =e,\mu$. Based on two types of $H\to W{W}^{\ast }$ decay topologies, one assuming the semileptonic decay mode $H\to W{W}^{\ast }\to {\ell }^{+}\nu jj$ and the other the fully leptonic decay mode $H\to W{W}^{\ast }\to {\ell }^{+}\nu {\ell }^{-}\bar{\nu }$, we perform a full simulation for signals and backgrounds. It is shown that, at the future HL-LHC, the branching ratio $Br(t\to uh)(Br(t\to ch))$ can be probed to $1.17(1.56)\times 10^{-3}$ for the same-sign di-lepton channel and to $7.1\times 10^{-4}(1.39\times 10^{-3})$ for the 3L channel at $3\sigma$ sensitivity.

Comments: version in Chinese Physics C