Precision Results from Lattice QCD – Claude Bernard

Date: Thu. March 31st, 2005, 4:15 pm-5:15 pm
Location: Rockefeller 301

At present the only means of carrying out nonperturbative calculations of the Strong Interactions from first principles is through large scale numerical simulations of Quantum Chromodynamics (QCD) on the lattice. These simulations promise to make possible stringent experimental tests of the Standard Model, as well as searches for new physics. Here, I discuss recent advances in Lattice QCD simulations that allow us to make computations in which all systematic errors are under control. With better algorithms and huge amounts of computer power, the effects of virtual quark-antiquark pairs — long neglected in the so called “quenched approximation” — can now be included. New understanding of the lattice-spacing and quark-mass dependence has then resulted in computations of unprecedented precision. Lattice QCD thus appears to be close to fulfilling its promise. Nevertheless, some key issues and problems still remain unsolved.