Heavy hybrid states from NRQCD

We present a quenched lattice calculation for the lowest lying $b\overline{b}g$-hybrid states in the framework of NRQCD using the leading order Hamiltonian up to $\mathcal{O}{(mv}^2)$. We demonstrate the existence of a nearly degenerate rotational band of states with an excitation energy approximately 1.6 GeV above the ${\rm Y}$ ground state. This lies around the $B{B}_J^{*}$-threshold, but well above the $B\overline{B}$-threshold. Therefore a heavy hybrid signal may well be detected if the center-of-mass energy in $B$-factories is raised a few hundred MeV to coincide with other resonances above the 4$S$ state. Our prediction is consistent with most phenomenological models and lattice calculations carried out in the static limit.