First determination of the charmed 0-- hybrid meson spectrum from lattice QCD

We compute from lattice QCD the ground and excited state masses of the charmed hybrid mesons ${\bar c} c g$, 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 4.441(36) and 4.760(55), and the first excited state masses are 6.753(457) and 7.165(120), being consistent with other lattice calculations. We predict for the first time from lattice QCD, the ground state mass of $0^{--}$ to be 6.003(167) and the first exited state mass to be 10.721(200).