Relativistic Effects in S-Wave Quarkonium Decay

Abstract

The decay widths of S-wave quarkonia ($\text{etc},\text{etb}\to \gg and\text{J},\text{U}\to \text{ee}$) are calculated on the basis of a quasipotential approach. The nontrivial dependence on relative quark motion of decay amplitude is taken into consideration via quarkonium wave function. It is shown that relativistic corrections may be large (10-50 %) and comparable with QCD corrections.

Comments: 10 pages, no figures