On Fermion Zero-Modes in Instanton $V-A$ Models With Spontaneous Symmetry Breaking

The left and right handed fermion zero-modes are examined. Their behaviour under the variation of the size of the instanton, $\ri$, and the size of the Higgs core, $\rh$, for a range of Yukawa couplings corresponding to the fermion masses in the electroweak theory are studied. It is shown that the characteristic radii of the zero-modes, in particlar those the left handed fermions, are locked to the instanton size, and are not affected by the variation of $\rh$, except for fermion masses much larger than those in the standard electroweak theory.