# GlueX Physics Lattice QCD Calculations

## Lattice QCD Calculations

• Hybrid Meson Calculations
• Toward the excited meson spectrum of dynamical QCD, Jozef J. Dudek, Robert G. Edwards, Michael J. Peardon, David G. Richards, Christopher E. Thomas, (2010), arXiv.
• Highly excited and exotic meson spectrum from dynamical lattice QCD, Jozef J Dudek, Robert G Edwards, David G Richards, Christopher E Thomas, (2009), arXiv.
• Decay width of light quark hybrid meson from the lattice, C. McNeile and C. Michael, Phys. Rev. D73, (2006), 074506, arXiv.
• Lattice calculation of 1-+ hybrid mesons with improved Kogut-Susskind fermions, C. Bernard et al., Phys. Rev. D68, (2003), 074505, arXiv.
• The heavy-quark hybrid meson spectrum in lattice QCD, J. Juge, J. Kuti and C. Morningstar, AIP Conf.Proc.688 (2004),193-207, arXiv.
• Hybrid meson decay from the lattice, C. McNeile, C. Michael and P. Pennanen, Phys. Rev. D65, (2002), 094505, arXiv.
• Ab initio study of hybrid anti-b g b mesons, K.J. Juge, J. Kuti and C.J. Morningstar, Phys. Rev. Lett.82 (1999), 4400-4403, PRL.
• Exotic mesons in quenched lattice QCD, C. Bernard et al. (MILC Collaboration), Phys. Rev. D56 (1997), 7039, PRD.
• Hybrid mesons from quenched QCD, P. Lacock, C. Michael, P. Boyle and P. Rowland, Phys. Lett. B401 (1996), 308-312, arXiv.
• Glueball Calculations
• Glueball spectrum and matrix elements on anisotropic lattices, Y. Chen et al., Phys. Rev. D73 (2006), 014516, PRD.
• The Glueball spectrum from an anisotropic lattice study, C. Morningstar et al., Phys. Rev. D60 (1999), 034509, PRD.
• Meson Spectrum Plots
• These plots are modified versions of those found in "Toward the excited ..." suitable for use in talks. These results are from dynamical studies with light and strange quarks - that is they are "unquenched". Please email dudek@jlab.org if you have any questions.
• File:Exotic summary.pdf Exotic $J^{{PC}}$ isospin=1 meson masses as a function of pion mass. The light pink circles are $1^{{-+}}$ quenched estimates from the references above, the darker pink circles are $1^{{-+}}$ dynamical estimates from the references above. The triangles are the new results on lattices of spatial volume $\sim (2{\rm {{fm})^{3}}}$ and $\sim (2.5{\rm {{fm})^{3}}}$ - the red points are $1^{{-+}}$, blue points $0^{{+-}}$ and green $2^{{+-}}$. Other exotic quantum numbers, like $0^{{--}}$, $3^{{-+}}$ are somewhat heavier.
• File:743 spectrum hybrids.pdf Meson spectrum, computed in the case of three quark flavours, but all as heavy at the real strange quark - this gives a pion mass of roughly 700 MeV. Same two volumes as above - lack of volume dependence adds weight to the assumption that these are 'single particle states'. Mass expressed in convenient units of the Omega baryon mass computed in the same calculation. Orange colouring suggests that states (including non-exotics) may be hybrids owing to their large overlap with QCD operators containing explicit gluonic structure.
• File:1mm.pdf Example of pion mass dependence of non-exotic $1^{{--}}$states. The fourth state is suspected to be a non-exotic hybrid meson.