Quantum chromodynamics (QCD) is the component of the
Standard Model of
elementary particle physics that governs the strong interactions. It
describes how quarks and gluons, the fundamental entities of strongly
interacting matter, are bound together to form strongly interacting
particles, such as protons and neutrons, and it determines how these
particles in turn interact to form atomic nuclei.
The Standard Model
has been enormously successful; however, our knowledge of it is incomplete
because it has proven extremely difficult to extract many of the most important
predictions of QCD, those that depend on the strong coupling regime of the
theory. To do so from first principles and with controlled systematic errors
requires large scale numerical simulations within the framework of
lattice gauge theory.
Such simulations are needed to address problems that are at the
heart of the Department of Energy's large experimental programs in high energy
and nuclear physics.
Our immediate objectives are to 1) calculate the effects of the strong interactions on weak interaction processes to the accuracy needed
to make precise tests of the Standard Model and to serch for evidence of physics beyond the Standard Model; 2) determine the properties
of strongly interacting matter under extreme conditions such as those that
existed in the very early development of the universe, and are created
today in relativistic heavy ion collisions; 3) calculate the masses of
strongly interacting particles and obtain a quantitative understanding of their internal structure. and 4) lay the foundations for investigations of strongly interacting sectors of new physics which may be discovered at the LHC.