  Taking the effective interaction between a quark and an anti-quark from
previous work, the dependendence on a regularization scale is removed in line
with the renormalization group. In order to emphasize the essential point, the
full spinor interaction is replaced by a model which includes only the Coulomb
and the hyperfine interaction. By adjusting the effective quark masses, the
only free parameters of the theory, the mass and the size of the pion are
reproduced, as well as the mass of all other pseudo-scalar mesons. Estimates
for the vector mesons are close to the empirical values. The model exposes
screening rather than strict confinement. The ionization thresholds are in
general much larger than the pion mass.
