Aida El-Khadra (University of Illinois)

Lattice QCD and Quark Flavor Physics

The strong interaction is a force which binds quarks, antiquarks and gluons together into protons, neutrons and other similar particles. This force is also responsible for binding protons and neutrons into nuclei. The theory which describes the strong interaction is Quantum Chromodynamics (QCD). It is part of the so-called standard model of particle physics, which successfully describes almost all our experimental observations in particle physics. However, a quantitative understanding of bound state properties from QCD requires nonperturbative methods. Lattice QCD is such a method. It is systematically improvable and controllable. Lattice QCD calculations use monte carlo methods, that require large scale numerical simulations, and hence significant computational resources. The scope of the simulations affects the precision of the calculations.

The lack of precision in understanding hadrons from the fundamental theory is one of the outstanding problems of particle physics. This problem also affects the experimental effort at the intensity frontier, in particular, on quark flavor physics. The goal of the intensity frontier effort is to search for new physics via confronting theory with precision experimental measurements. Since QCD effects are a dominant contribution to the standard model expectation for many of these processes, precise lattice QCD calculations are an essential ingredient in this effort.

In this talk I review the status of lattice-QCD calculations relevant to quark flavor physics. I describe recent developments that are moving these calculations towards their precision goals and their impact on the landscape of lattice flavor physics calculations.