Why quarkonium hybrid coupling to two S-wave heavy-light mesons is not suppressed

Abstract

We examine the couplings of quarkonium hybrids to heavy-light meson pairs in the Born-Oppenheimer approximation for QCD. The lowest hybrid multiplets consist of bound states of the ${\Pi }_u$ and ${\Sigma }_u^{-}$ potentials. We find that the ${\Sigma }_u^{-}$ potential can couple to pairs of $S$-wave mesons through string breaking, while the ${\Pi }_u$ potential cannot. From this observation, we derive model-independent selection rules that contradict previous expectations that quarkonium hybrids are forbidden to decay into pairs of $S$-wave mesons. These Born-Oppenheimer selection rules are consistent with the partial decay widths of the lowest charmonium hybrid with exotic quantum numbers $J^{PC}=1^{-+}$ recently calculated in lattice QCD.

4 pages, 1 table; v2: simplified text and equations, added discussion of branching ratios, typos corrected, various minor edits

References in corpus (11)

• Excited and exotic charmonium spectroscopy from lattice QCD
• Hybrid Mesons
• Excited and exotic charmonium, $D_s$ and $D$ meson spectra for two light quark masses from lattice QCD
• String breaking by light and strange quarks in QCD
• Bottomonium resonances with $I=0$ from lattice QCD correlation functions with static and light quarks
• Heavy hybrid decays to quarkonia
• Heavy Hybrid Decays in a Constituent Gluon Model
• Hyperfine splittings of heavy quarkonium hybrids
• Heavy-Quark spin symmetry breaking in the Born-Oppenheimer approximation
• Heavy meson thresholds in Born-Oppenheimer Effective field theory
• Eight very excited spectra and one possible axion in SU(3) lattice gauge theory

Cited by in corpus (4)

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• Model-independent predictions for decays of hidden-heavy hadrons into pairs of heavy hadrons
• Unravelling Pentaquarks with Born--Oppenheimer effective theory
• Effect of continuum states on the double-heavy hadron spectra