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arXiv · 2306.17120

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

R. Bruschini
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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.

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R. Bruschini. 2023-06-29. Why quarkonium hybrid coupling to two S-wave heavy-light mesons is not suppressed. https://doi.org/10.1103/physrevd.109.l031501

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