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 Ξ uβ and Ξ£uββ potentials. We find
that the Ξ£uββ potential can couple to pairs of S-wave mesons through
string breaking, while the Ξ uβ 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
JPC=1β+ recently calculated in lattice QCD.Comment: 4 pages, 1 tabl