No abstract

The spectrum of the Υ system is investigated using the Nonrelativistic Lattice QCD approach to heavy quarks and ignoring light quark vacuum polarization. We find good agreement with experiment for the Υ, Υ ′ , Υ ′′ and for the center of mass and fine structure of the χ b -states. The lattice calculations predict b b D-states with center of mass at (10.20 ± 0.07 ± 0.03)GeV. Fitting procedures aimed at extracting both ground and excited state energies are developed. We calculate a nonperturbative dispersion mass for the Υ(1S) and compare with tadpole-improved lattice perturbation theory.

We present results for Charmonium spectroscopy using Non-Relativistic QCD (NRQCD). For the NRQCD action the leading order spin-dependent and next to leading order spin-independent interactions have been included with tadpole-improved coefficients. We use multi-exponential fits to multiple correlation functions to extract ground and excited S states. Splittings between the lowest S, P and D states are given and we have accurate values for the S state hyperfine splitting and the χ c fine structure. Agreement with experiment is good -the remaining systematic errors are discussed.