Neutron electric dipole moment due to Higgs exchange in Left-Right   symmetric models
  In this paper we study the neutron electric dipole moment (EDM) due to Higgs boson exchange in Left-Right symmetric models. In pseudo-manifest Left-Right symmetric models, the neutral Higgs contribution is smaller than that from the charged Higgs. The charged Higgs contribution at the two loop level can be as large as the experimental upper bound. In non (pseudo) manifest Left-Right symmteric models, the neutral Higgs exchange contribution can reach the experimental upper bound. The Higgs exchange contributions can be more important than the ones from W-boson exchange due to $W_L - W_R$ mixing. 
D. Chang, Xiao-Gang He, W.-Y. Keung, B.H.J. McKellar, and D. Wyler