Radiative corrections to production in the two Higgs doublet model

Abstract

Electroweak corrections to the tt production cross section in electron-positron collisions have been evaluated in the two-doublet model in the threshold region. The dominant corrections are shown to originate from scalar Higgs exchange and can be enhanced in the two Higgs doublet model by tuning the Yukawa couplings. The energy dependence of these corrections has been studied with emphasis on the Higgs exchange contribution. The large correction resulting from light-Higgs exchange is strongly damped with increasing energy.