ABSTRACT:
Lattice QCD calculations now include the effects of 2 light sea quarks and 1 strange sea quark through the use of an improved staggered fermion action; consequently, calculations important to quark flavor physics are free of the unsystematic errors that infected previous calculations. Furthermore, the work of the previous decade to reduce discretization errors, to tame lattice perturbation theory, to control light quark mass extrapolations, and to implement
heavy lattice quarks is finally converging to yield realistic, accurate calculations. In this talk I discuss some important recent innovations we employ, show tests of the methodology, and present our current results. I conclude by showing the impact of the results on constraints of Standard Model parameters and by mapping the route for further improvement.
