On the leptonic partial widths of the excited psi states

TL;DR

This paper refines the understanding of excited psi states by analyzing experimental R-value data, revealing multiple possible leptonic partial widths and impacting charmonium spectroscopy interpretations.

Contribution

It provides four possible solutions for the leptonic partial widths of psi(4040), psi(4160), and psi(4415) based on precise experimental data, clarifying previous ambiguities.

Findings

Four solutions for leptonic widths identified

Previous single-solution assumption challenged

Implications for charmonium state interpretations

Abstract

The resonance parameters of the excited psi-family resonances, namely the psi(4040), psi(4160), and psi(4415), were determined by fitting the R-values measured by experiments. It is found that the previously reported leptonic partial widths of these states were merely one possible solutions among a four-fold ambiguity. By fitting the most precise experimental data on the R-values measured by the BES collaboration, this work presents all four sets of solutions. These results may affect the interpretation of the charmonium and charmonium-like states above 4GeV/c^2.