Study of the Decoupling of Heavy Fermions in a Z_2 Scalar-Fermion Model
Abstract
According to one-loop perturbation theory, fermions whose masses are totally generated from Yukawa couplings do not decouple in the heavy mass limit. We investigate this issue nonperturbatively in a 4-dimensional
Z
2
scalar-fermion model with staggered fermions. Our data at intermediate and stronger Yukawa couplings on
8
4
and
12
4
lattices suggest the nondecoupling of heavy fermions as predicted from one-loop calculation. However, at the strongest Yukawa coupling where a possible multi-critical point may come into play, we cannot be conclusive.