Abstract
The phase space modification associated with a nonvanishing effective mass for the primary gluons, GeV for the and GeV for the , is shown to be crucial for a consistent description of the photon spectrum from their radiative decays and for the determination of from the recent, precise quarkonia decay branching ratios. In this approach, the role of the relativistic corrections is marginal and, after applying the -dependent corrections, a good agreement is obtained with the relative perturbative running, and , and with the extrapolation from deep inelastic scattering. On the other hand, for , the analysis of all experimental and quarkonia branching ratios is consistent with the same effective value of the strong interaction coupling constant . By assuming a "genuine," i.e., process-independent, gluon mass (∼ 1.2 GeV or higher) to be dynamically generated one predicts a strong suppression of the gluon splitting process at the and the hadronic final states should be mainly produced via gluon fusion into light pairs thus effectively reducing the fitted value of from the photon spectrum in . The gluon fusion mechanism allows us to explain the structure of the hadronic final states observed in decays and their close similarity to the continuum hadrons annihilation at comparable center of mass energies.
- Received 26 July 1993
DOI:https://doi.org/10.1103/PhysRevD.49.1293
©1994 American Physical Society