Dear Dr. Rowland,
A vert nice essay. I especially like the idea from Laughlin that fractional chrges may be an emergent feature a la fractional quantum Hall effect.
I recall that the Han-Nambu model was equivalent to the standard quark picture, but I thought that the R-ratio might provide a way to distinguish teh two? Briefly the R-ratio is
R= sigma(e+e- --> q q-bar) / sigma (e+e- --> mu+ mu-)
i.e. it was the ratio of the total cross section of electron, positron to quark,anti-quark divided by the total cross section for electron, positron to mu-, mu+. This ratio then provides a glimpse into the charge and color assignments. In the standard quark picture for a single quark, anti-quark (u-quark say)
R= N_c (q_u)^2
where N_c is the number of colors and q_u is the electric charge of the up-quark. In scatterinng experimetns up to the s-quark mass (but below c-quark) one finds (to tree level)
R=3(4/9+1/9+1/9) = 2
Everytime a new energy is reached where a new quark can be created the R-ration jumps so for exmaple when one has an energy to include the c-quark this becomes
R=3(4/9+1/9+1/9+4/9)=10/3
This relationship for R (and the first order log corrections) has been tested nd confirmed. What does the Han-Nambu model give for the R-ratio? This might be a tricky test since it depends on the square of the charges and the average of the square is not always the square of the average. In any case it would be a good test of the Han-Nambu model.
One should also check if the chiral anomaly cancellation of the Standard Model works since this relates the various charges of leptons with quarks in order that the anomaly cancel. However even thhough I did not check this my feeling is that the Han-Nambu model will work for this since in the anomaly (at least to one-loop) the anomaly depends linearly on the various charges rather than quadratically as for the R-ratio.
Best,
Doug