Mixed Heavy Quark Hybrid Mesons, Decay Puzzles, and RHIC

TL;DR

This paper estimates hybrid admixtures in heavy quarkonium states using QCD Sum Rules, explaining decay puzzles and predicting heavy quark production at RHIC.

Contribution

It provides the first quantitative estimates of hybrid components in Charmonium and Upsilon states, linking them to decay anomalies and RHIC predictions.

Findings

$ ho- ext{pi}$ puzzle explained by hybrid admixture

Unusual $\sigma$ decay patterns accounted for

Predictions for heavy quark production at RHIC

Abstract

We estimate the energy of the lowest Charmonium and Upsilon states with hybrid admixtures using the method of QCD Sum Rules. Our results show that the $\Psi'(2S)$ and $\Upsilon(3S)$ states both have about a 50% admixture of hybrid and meson components. From this we find explanations of both the famous $\rho-\pi$ puzzle for Charmonium, and the unusual pattern of $\sigma$ decays that have been found in $\Upsilon$ decays. Moreover, this picture can be used for predictions of heavy quark production with the octet model for RHIC.