Revisiting the heavy vector quarkonium leptonic widths *

Abstract

We revisit the heavy quarkonium leptonic decays and using the Bethe-Salpeter method. The emphasis is on the relativistic corrections. For the decays, the relativistic effects are %, %, %, % and %, respectively. For the decays, the relativistic effects are %, %, %, % and %, respectively. Thus, the relativistic corrections are large and important in heavy quarkonium leptonic decays, especially for the highly excited charmonium. Our results for are consistent with the experimental data.