EFFECTIVE GLUON MASS AND THE DETERMINATION OF ALPHA(S) FROM J PSI ANDY-BRANCHING RATIOS/

The phase space modification associated with a nonvanishing effective mass for the primary gluons, M(g)=0.66+/-0.08 GeV for the J/psi and M( g)=1.17+/-0.08 GeV for the gamma, is shown to be crucial for a consist ent description of the photon spectrum from their radiative decays and for the determination of alpha(s) from the recent, precise quarkonia decay branching ratios. In this approach, the role of the relativistic corrections is marginal and, after applying the M(g)-dependent correc tions, a good agreement is obtained with the relative perturbative run ning, alpha(s)(m(c))similar to 0.30+/-0.02 and alpha(s)(m(b))similar t o 0.21+/-0.01, and with the extra-polation from deep inelastic scatter ing. On the other hand, the M(g)=0, the analysis of the experimental c (c) over bar and b (b) over bar quarkonia branching ratios is consist ent with the same effective value of the strong interaction coupling c onstant alpha(s)(eff)similar to 0.185+/-0.010. By assuming a ''genuine ,'' i.e., process-independent, gluon mass (similar to 1.2 GeV or highe r) to be dynamically generated one predicts a strong suppression of th e gluon splitting process at the J/psi and the hadronic final states s hould be mainly produced via gluon fusion into light q (q) over bar pa irs thus effectively reducing the fitted value of M(g) from the photon spectrum in J/psi-->gamma+X. The gluon fusion mechanism allows us to explain the structure of the hadronic final states observed in J/psi d ecays and their close similarity to the continuum e(+)e(-)-->hadrons a nnihilation at comparable center of mass energies.