Monopoles and hadron spectrum in quenched QCD

We study quenched hadron spectra with Wilson fermion in abelian gauge fields extracted by maximal abelian projection and in fields induced by monopoles on $16^3 \times 32 $ and $ 12^3 \times 24$ lattices. Pion mass squared and quark mass defined through the axial Ward identity satisfy the PCAC relation. Gross features of the light hadron spectra are almost similar to those in SU(3) gauge fields if normalization is made by the square root of the string tension. It is also shown that no sizable dynamical mass generation is found in the present range of $\kappa$ when the monopole degree of freedom is removed from the abelian fields or from the SU(3) gauge fields.