Hadronic wave functions in the instanton model

In this paper we wish to study hadronic wave functions using an instanton model for the QCD vacuum. The wave functions are defined in terms of gauge-invariant Bethe-Salpeter amplitudes which we have determined numerically using a Monte Carlo simulation of the instanton ensemble. We find that the pion and the proton, as well as the meson and the , have very similar wave functions but observe a sizable splitting between mesons or baryons with different spin. We compare our results with data obtained in lattice gauge simulations.