The Upsilon Spectrum from Lattice QCD with 2+1 Flavors of Dynamical   Quarks
  We describe the bottomonium spectrum obtained on the MILC configurations which incorporate 2+1 flavors of dynamical quarks. We compare to quenched and 2 flavor results also on MILC configurations. We show that the lattice spacing determination using different quantities shows clear signs of convergence with 2+1 flavors and give results for the leptonic width and hyperfine splitting, in the form of the ratio of the 1st excited state of the Upsilon to that of the ground state. 
A. Gray, C. Davies, M. Alford, E. Follana, J. Hein, G. P. Lepage, Q.   Mason, M. Nobes, J. Shigemitsu, H. Trottier, M. Wingate