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managed for the U.S. Department of Energy
by Brookhaven Science Associates, a company
founded by Stony Brook University and Battelle

The Relativistic Heavy Ion Collider:
Hot on the Trail of Quark-Gluon Plasma

After just two years, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven Lab — the world’s newest and largest particle accelerator for nuclear physics research — has produced enough data to fill more than 40 scientific papers and get physicists around the world talking about what it all means. RHIC’s goal is to recreate and study what is called “quark-gluon plasma,” or QGP, an elusive form of hot, dense matter thought to have last existed in bulk a mere instant after the birth of our universe.

So far, the scientists are seeing everything from expected milestones to intriguing surprises.

“Some of the results are rather easily put into the theoretical picture that we had developed before RHIC started taking data, but some of the results are quite puzzling,” says Thomas Kirk, Brookhaven’s Associate Laboratory Director for High Energy and Nuclear Physics. “It is too early to say that we have discovered the quark gluon plasma, but not too early to mark the tantalizing hints of its existence.”

Unlike the nuclei of ordinary atoms, which are composed of protons and neutrons, QGP is expected to be a hot soup-like mixture of unbound quarks and gluons — the components that make up protons and neutrons — but ones freed from their confines within these familiar particles.

Everything in the current universe — from the planets and stars to people and their pets —once existed as this state of matter, before cooling and condensing to form particles. Learning how the QGP behaves will help the 1,000 or so scientists working on RHIC — and the rest of world — gain a better understanding of the structure of matter and the early history of our universe.

NEXT> Cooking Up Quark Soup

The U.S. Department of Energy's Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies. Brookhaven also builds and operates major facilities available to university, industrial, and government scientists. The Laboratory is managed by Brookhaven Science Associates, a limited liability company founded by Stony Brook University and Battelle, a nonprofit applied science and technology organization.