Renormalized Yukawa couplings from the lattice

Renormalized Yukawa couplings, YR, are evaluated numerically in the single component lattice λφ4 theory coupled to staggered fermions. For a wide range of bare couplings, the renormalized YR is found to be 'samll' (< or approx.1.5) whenever physical scalar and fermion masses have dropped below about one half the cutoff scale. In these cases Yukawa coupling generated fermion masses are never much larger than the symmetry breaking scale v=<φR>. The simulations have been performed using the hybrid Monte Carlo algorithm for dynamical fermions. (orig.)