In this paper, we study the anomalous flavor changing neutral current Yukawa interactions between the top quark, the Higgs boson, and either an up or charm quark ($tqH,q=u,c$). We probe these couplings in $e^{-}p\to {\nu }_e\overline{t}\to {\nu }_{e}H\overline{q}$ and the channel $e^{-}p\to {\nu }_{e}Hb$. Both channels are induced by charged current interactions through $e^{-}p$ collision at the Large Hadron Electron Collider (LHeC). We study the signatures with the Higgs decay modes $H\to \gamma \gamma ,b\overline{b}$ and ${\tau }^{+}{\tau }^{-}$. Our results show that the flavor changing couplings ${\kappa }_{tqH}$ can be probed down to a value of 0.0162 in $e^{-}p\to {\nu }_e\overline{t}\to {\nu }_{e}H\overline{q}$ with $H\to b\overline{b}$ at a 14 TeV LHeC with a 150 GeV electron beam and $200{\mathrm{fb}}^{-1}$ luminosity. This value of the coupling corresponds to the branching ratio $\mathrm{Br}(t\to qH)=1.34\times {10}^{-4}$.

• Received 4 February 2015

DOI:https://doi.org/10.1103/PhysRevD.92.074015