Enhancing $thj$ Production from Top-Higgs FCNC Couplings

Abstract

In this paper, we study the single top and Higgs associated production $pp\to thj$ in the presence of top-Higgs FCNC couplings(${\kappa }_{tqh},q=u,c$) at the LHC. Under the current constraints, we find that the cross section of $pp\to thj$ can be sizably enhanced in comparison with the SM predictions at 8 and 14 TeV LHC. We also find that the full cross section of $pp\to thj$ with ${\kappa }_{tch}$ is larger than the resonant cross section of $pp\to t\bar{t}\to thj$ by a factor 1.16 at 8 TeV LHC and 1.12 at 14 TeV LHC, respectively. We further explore the observability of top-Higgs FCNC couplings through $pp\to t(\to b{\ell }^{+}{\nu }_{\ell })h(\to \gamma \gamma )j$ and find that the branching ratios $Br(t\to qh)$, $Br(t\to uh)$ and $Br(t\to ch)$ can be respectively probed to $0.12\%,0.23\%$ and $0.26\%$ at $3\sigma$ sensitivity at 14 TeV LHC with $\mathcal{L}=3000$ fb${}^{-1}$.

Comments: 15 pages, 7 figures, references and discussions added, accepted by JHEP