Constituent Quark Pair Production in a Potential Model of Mesons

The coupling of primitive qq meson states to four -quark qq qq states is investigated. The basic mechanism is the production of a massive quark-antiquark pair. The Feynman diagram for this process is considered and, with suitable approximations, this diagram yields a coupling operator. The heavy meson systems cc and bb are treated in some detail. Energy shifts for the first three J('P) = 1('-) states in charmonium are found to be in the range 50-80 MeV. The calculated width of the state (psi)'' is 14 MeV. The decay (psi)'(--->)(psi)(eta) is treated as a two-stage process of pair production followed by quark exchange and a width of 1.6 keV is obtained. An attempt is made to study the lighter meson systems ss and nn. Using a coupling operator similar to that used for the heavy mesons, the widths of the (phi) and (rho) mesons are determined to within an order of magnitude.