QCD tells us that protons and neutrons are made of bundles of particles called quarks held together by other particles called gluons - the strongest imaginable glue. According to QCD, quarks and gluons are the most fundamental particles in nature, the essential building blocks of all matter. The theory has withstood many tests, says MILC physicist Robert Sugar of the University of California, Santa Barbara, but it's been difficult to extract predictions that can be measured against experiment. Because of the complexities of the theory, QCD is one of the most demanding computational projects in science. Through an extensive series of computations, MILC researchers have tested improved actions for a particular formulation of QCD known as Kogut-Susskind or staggered quarks.
Tests show a significant reduction in finite-lattice spacing effects.
As a result of this success, MILC is embarking on a major program of production runs.