Christopher Monahan (Cambridge):

Perturbative Renormalisation of the Lattice NRQCD Action

Abstract:

Precise nonperturbative predictions of heavy quark bound states are required to constrain the fundamental parameters of the Standard Model. Lattice QCD offers the only available method for nonperturbative QCD calculations. However present lattice spacings are too coarse to simulate heavy quarks directly. An effective nonrelativistic theory (NRQCD) is used to discretise the heavy degrees of freedom. Current lattice simulations are sufficiently precise that one-loop contributions to tree-level quantities are significant. We calculate the one-loop renormalisation of the heavy quark propagator NRQCD using automated lattice perturbation theory. We also present the one-loop corrections to the higher order kinetic terms of the NRQCD action.