Numerical simulation of heavy fermions in an SU(2)_L x SU(2)_R symmetric   Yukawa model
  An exploratory numerical study of the influence of heavy fermion doublets on the mass of the Higgs boson is performed in the decoupling limit of a chiral $\rm SU(2)_L \otimes SU(2)_R$ symmetric Yukawa model with mirror fermions. The behaviour of fermion and boson masses is investigated at infinite bare quartic coupling on $4^3 \cdot 8$, $6^3 \cdot 12$ and $8^3 \cdot 16$ lattices. A first estimate of the upper bound on the renormalized quartic coupling as a function of the renormalized Yukawa-coupling is given. 
C. Frick, L. Lin, I. Montvay, G. Munster, M. Plagge, T. Trappenberg,   H. Wittig