Zusammenfassung
We analyze the relativistic corrections to annihilation rates of S-wave
quarkonia within the framework of NRQCD. We show that order v^2 corrections can
be expressed in terms of the heavy quark pole mass and the quarkonium mass. The
ratio of hadronic to radiative annihilation rates for eta\_b and eta\_c can
therefore be predicted accurately. The contributions of color-octet operators
to the hadronic decay rates of spin-triplet quarkonia are shown to be
significant, even though they arise at order v^4 in the velocity expansion. We
provide a rough estimate of the color-octet contributions and extract the value
of alpha\_s from the experimental data on Upsilon decays.
Nutzer