Ambiguities in the calculation of leptonic decays of excited heavy quarkonium

Abstract

We point out that the determination of the leptonic decay width of radially-excited quarkonia is strongly dependent on the position of the node typical of these excitations. We suggest that this feature could be related with the longstanding rho-pi puzzle.

Comments: Presented at HADRONIC PHYSICS (HLPR 2004): Joint Meeting-Heidelberg-Liege-Paris-Rostock, Spa, Belgium, 16-18 December 2004, 11 pages, 11 figures, LaTeX, uses aip-6s.clo, aipproc.cls and aipxfm.sty (included); Figure 9 corrected