Yukawa Corrections to Top Quark Production at the LHC in Two-   Higgs-Doublet Models
  The O(alpha m_t^2/m_W^2) corrections to top quark pair production by gluon-gluon fusion at the LHC are calculated in two-Higgs-doublet models. We find that the correction to the cross-section can exceed about -10% for certain parameter values. 
Hong-Yi Zhou, Chong-Sheng Li, Yu-Ping Kuang