Minimal generalization of the 5-quark model of Ψ particles
Krasnikov N.V., Kuz'min V.A., Tavkhelidze A.N., Chetyrkin K.G.
The 5-quark model of ψ particles is generalized by introducing additional quarks that are degenerate in mass and charge with respect to the initial fourth and fifth quarks. The proposed generalization preserves the main consequences of the 5-quark model and makes it possible to explain qualitatively a number of additional facts.