Resummation of QCD corrections to the eta(c) decay rate - art. no. 114008

We examine the ratio of the decay rate of the eta, into light hadrons to th e decay rate into photons and find that most of the large next-to-leading-o rder (NLO) correction is associated with running of the strong coupling alp ha We resum Such contributions by analyzing final-state chains of vacuum-po larization bubbles. We show that the nonperturbative parts of the bubble ch ains can be absorbed into a color-octet matrix element, once one has used c ontour deformations, of the phase-space integrals to cancel certain contrib utions. We argue that these contributions are incompatible with the uncerta inty principle, We also argue that perturbation theory is reliable only if one carries out the phase-space integrations before the perturbation summat ion. Our results are in good agreement with experiment and differ considera bly from those that one obtains by applying the scale-setting method of Bro dsky. Lepage. and Mackenzie to the NLO result.