QUARK MASS EFFECTS IN $\psi\to B\bar B$ DECAYS

Abstract

It is emphasized that since intermediate distances, in a range lying between confinement and asymptotic freedom, are probed in ψ decays, the quarks that constitute the hadrons produced in these decays should be considered as "constituent quarks" rather than "current quarks", as chiral-symmetry breaking effects should probably be already efficient in that range. In the case of ψ decays into baryon-antibaryon pairs, it is shown that the resulting quark mass effects may be important, especially when studying the angular distributions of the baryons emitted. Agreement with experimental data is found for these distributions, using a very simple nonrelativistic static quark model where each constituent quark in a baryon is assumed to have an effective mass of about a third of the baryon mass.