BINDING-ENERGY OF QUARKONIUM SYSTEMS AND THE MASS-SPECTRA

We show that if a quark (or antiquark) with mass ma is replaced by a heavier quark (or antiquark) with mass mb in a quarkonium state, the increase of the mass of the quarkonium system is substantially less than mb-ma due to the increase of the binding energy (in some cases it is only 16 of mb-ma). It is shown that for the heavy quarkonia the F-family mesons get close to the D-family mesons for a large class of potentials. The spectrum of all known mesons is explained if the change of the binding energy is taken into account. © 1979 The American Physical Society.