Heavy Quarkonium ($1^{--}$) Meson-Hybrid Mixing from QCD Sum Rules

Abstract

We use QCD Laplace sum-rules to explore mixing between conventional mesons and hybrids in the heavy quarkonium vector $J^{PC}=1^{--}$ channel. Our cross-correlator includes perturbation theory and contributions proportional to the four-dimensional and six-dimensional gluon condensates. We input experimentally determined charmonium and bottomonium hadron masses into both single and multi-resonance models in order to test them for conventional meson and hybrid components. In the charmonium sector we find evidence for meson-hybrid mixing in the $J/\psi$ and a $\approx 4.3$ GeV resonance. In the bottomonium sector, we find that the ${\rm Y}(1S)$, ${\rm Y}(2S)$, ${\rm Y}(3S)$, and ${\rm Y}(4S)$ all exhibit mixing.

Comments: QCD-17 conference proceedings article