Estimate of the charmed0--hybrid meson spectrum from quenched lattice QCD

We compute from quenched lattice QCD the ground state masses of the charmed hybrid mesons $\overline{c}cg$, with exotic quantum numbers $J^{PC}=1^{-+}$, $0^{+-}$ and $0^{--}$. The $0^{--}$ hybrid meson spectrum has never been provided by lattice simulations due to the difficulties to extract high gluonic excitations from noise. We employ improved gauge and fermion actions on the anisotropic lattice, which reduce greatly the lattice artifacts, and lead to very good signals. The data are extrapolated to the continuum limit, with finite size effects under well control. For $1^{-+}$ and $0^{+-}$ hybrid mesons, the ground state masses are 4.405(38) GeV and 4.714(52) GeV. We predict for the first time from lattice QCD, the ground state mass of $0^{--}$ to be 5.883(146) GeV.