Yukawa corrections to single top-quark production at the Fermilab Tevatron in the two-Higgs-doublet models

We calculate Yukawa corrections of order ${\mathrm{\alpha }}_{\mathrm{ew}}$ $M_t^2$ ${/M}_W^2$ to single top-quark production via q${\overline{q}}^{\prime }$→t$\overline{b}$ at the Fermilab Tevatron in the two-Higgs-doublet models. In our calculation we also keep the terms proportional to $M_b^2$ ${\tan }^2$β since their effects may become rather important for large tanβ. The corrections can amount to more than a 15% reduction in the production cross section relative to the tree-level result in the general two-Higgs-doublet model, and a 10% enhancement in the minimal supersymmetric model, which might be observable at a high-luminosity Tevatron.