Nonrelativistic bound states in quantum field theory

Nonrelativistic bound states are studied using an effective field theory with an expansion in the velocity v of the bound state constituents. Logarithms of v can be summed using the velocity renormalization group. This calculational method provides new insights into the nature of the perturbation series for QED bound states such as Hydrogen and Positronium, and allows one to compute the energy series up to order α8 ln3 α, which is necessary for the present comparison between theory and experiment. The formalism can also be applied to nonrelativistic QCD problems such as the Υ, and t-bart production near threshold