Excited and exotic charmonium, $\textit{D}$$_{s}$ and $\textit{D}$ meson spectra for two light quark masses from lattice QCD

Cheung, Gavin ; O'Hara, C ; Moir, Graham ; Peardon, M ; Ryan, SM ; Thomas, Christopher Edward ; Tims, D (2016-12-19)


We present highly-excited charmonium, $\textit{D}$$_{s}$ and $\textit{D}$ meson spectra from dynamical lattice QCD calculations with light quarks corresponding to $\textit{M}$$_{π}$ ∼ 240 MeV and compare these to previous results with $\textit{M}$$_{π}$ ∼ 400 MeV. Utilising the distillation framework, large bases of carefully constructed interpolating operators and a variational procedure, we extract and reliably identify the continuum spin of an extensive set of excited mesons. These include states with exotic quantum numbers which, along with a number with non-exotic quantum numbers, we identify as having excited gluonic degrees of freedom and interpret as hybrid mesons. Comparing the spectra at the two different $\textit{M}$$_{π}$ , we find only a mild light-quark mass dependence and no change in the overall pattern of states.