APPLICATIONS

Particle Physicists are embarking on a new attempt to solve the mysteries of quarks with the completion of the three most powerful supercomputers ever applied to this problem, including one at the University of Edinburgh for use by the UK Quantum Chromodynamics (UKQCD) collaboration of scientists from seven British Universities. Quarks are the fundamental particles that make up 99.9% of ordinary matter; yet it is impossible to examine a single quark in the laboratory. Consequently, some of the basic properties of quarks are not known, such as their precise masses or why they exist in six different types. Quarks are bound together by the Strong Force, which is weak when the quarks are close, but increases steadily as you try to separate them, making it impossible to isolate a single quark. Instead, the theory describing the Strong Force, called Quantum Chromodynamics (QCD), has to be simulated on supercomputers. The Edinburgh computer is the first of three similar machines and has been operating since January 2005. The second computer is being inaugurated today at the RIKEN Brookhaven Research Center in Brookhaven National Laboratory in the USA. The third is part of the U.S. Department of Energy Program in High Energy and Nuclear Physics, and is also installed at Brookhaven where it is currently undergoing testing. The computers are built with processing chips specifically designed for the purpose, known as QCD-on-a-chip, or QCDOC for short. A little slower than the microprocessor in your laptop, the QCDOC chip was designed to consume a tenth of the electrical power, so that tens of thousands of them could be put into a single machine. The computers were designed and built jointly by the University of Edinburgh, Columbia University (USA), the RIKEN Brookhaven Research Center (USA) and IBM. Each QCDOC machine operates at a speed of 10 Teraflops, or 10 trillion (i.e. million million) floating point operations per second. By comparison, a regular desktop computer operates at a few Gigaflops (a thousand million floating point operations per second), whilst IBM's BlueGene, a close relative of QCDOC and the fastest computer in the world, operates at over 100 Teraflops. Edinburgh's machine and part of the QCDOC development costs were funded through a Joint Infrastructure Fund Award of £6.6million administered by the Particle Physics and Astronomy Research Council, who also fund the UK scientists in this field. Professor Richard Kenway, who led UK participation in the QCDOC Project, said "After five years building this machine, it's exhilarating to be able to compute in days things which take everybody else months. Now we are about to run QCDOC for months to do the most realistic QCD simulation yet. It's like standing on the shore of a new continent after a long voyage, we've chosen our path of exploration, but we don't know what we're going to find." Professor Richard Wade, Chief Executive of the Particle Physics and astronomy Research Council welcomed the start of the QCDOC supercomputer saying "The UKQCD collaboration has been a world-leading group for some years, producing very elegant analysis methods to make the most of available computing resources. With the power of the new supercomputer at their fingertips, they will be able to make crucial advances to our understanding of fundamental particles like quarks."