Heavy Hybrids: decay to and mixing with Heavy Quarkonium

Abstract

We report on a recent QCD based research on hybrid mesons containing cc̄ or bb̄ quarks. We present results for the spectrum, the decay widths to heavy quarkonium, and the role of mixing with the latter. We point out that mixing with heavy quarkonium provides a potentially large source of spin symmetry breaking. We identify candidates to hybrid mesons among the so called XYZ states in the charmonium and bottomonium spectrum.