Fit of charmonium and upsilon spectra by a common potential V0+A log(1+r)

We show that both charmonium and upsilon spectra can be simultaneously fitted by a potential of the form V(r)=-1.71 + 1.067 log(1 + r). It is found that the spin-averaged masses, fine-hyperfine splittings and leptonic decay width ratios of these spectra can be well understood without taking into account the short distance part of the potential as suggested by QCD. We make several predictions for the banti b spectra which could hopefully be tested in the near future. (orig.)