NMSU branding

New Mexico State University

New Mexico State University

News Center




Physicists hope to re-create matter from dawn of universe

New Mexico State University physicists are taking part in a huge experiment at Brookhaven National Laboratory in Long Island that will attempt to re-create a state of matter scientists believe existed briefly when the universe was only a fraction of a second old.



Staff and students at the NMSU Advanced Manufacturing Center gather in and around the electronics support structure they built for the muon detector system of the PHENIX Experiment at Brookhaven National Laboratory in Long Island.

The results, say Stephen Pate and Vassili Papavassiliou, could go a long way toward helping scientists understand the origin of the universe and the nature of all matter.

In May, Brookhaven's Relativistic Heavy Ion Collider (RHIC) will begin smashing the nuclei of gold atoms together at such high energy levels that they are expected to melt temporarily into a soup of nature's most basic particles.

Physicists know that protons and neutrons, which form the nucleus of every atom, are made of still-smaller particles called quarks and gluons, but these particles normally are bound together inseparably. The RHIC collisions will generate such temperatures -- more than a trillion degrees Centigrade, thousands of times hotter than the sun -- that the particles are expected to be freed momentarily in a state of matter known as quark-gluon plasma.

In essence, scientists will be observing a condition that is thought to have lasted for mere microseconds after the "big bang," which theorists believe was the dawn of the universe some 10 billion years ago. As the universe quickly expanded and cooled, according to the big bang theory, the quarks and gluons joined in various combinations to create the basic particles of all matter in the universe.

Pate and Papavassiliou are looking forward to some surprises at Brookhaven.

"We have never seen particles heated to these temperatures before," Pate said. "A lot of what we see will be a surprise. Think of it this way: If you are familiar only with ice and someone heats it up to make liquid water for the first time, it's something entirely new that behaves in ways that are unexpected to you."

Physicists have always been fond of taking apart the building blocks of matter to see how they work, and as the objects of their interest get smaller the tools they use tend to get bigger. The NMSU physicists, along with scientists from Los Alamos Laboratory, the University of New Mexico and more than 40 other institutions in 12 countries, are collaborating on the PHENIX project at Brookhaven.

PHENIX is one of five experiments located around RHIC's 2.4-mile ring, each responsible for observing different aspects of the high-energy particle collisions. Two of the five require apparatus the size of a large building, Papavassiliou said, and the other three are more room-sized. The 4,000-ton PHENIX is one of the big ones, and more than 400 scientists are collaborating on this part of the RHIC experiment.

The New Mexico group is responsible for PHENIX's muon detectors, massive devices of magnets, steel plates and electronics designed to observe the behavior of muons -- one of many kinds of particles that will be created as by-products of the gold ion collisions.

Some detector components have been built by NMSU students at the university's Advanced Manufacturing Center. Other parts are being made at Los Alamos. The final assembly is being done at Brookhaven because the finished detector would be too big to transport.

The Brookhaven collaborators are not the only group that has been attempting to create and observe quark-gluon plasma. Scientists at CERN, the European laboratory in Geneva, announced in February they had gathered convincing evidence over the past several years that they had created a new state of matter in which quarks and gluons are not confined. While stopping short of pronouncing this the theoretically predicted quark-gluon plasma, they noted that it had many of the expected features of such a state and urged further experimental studies.

The CERN experiments smashed lead ions into a stationary target. Brookhaven, using head-on collisions that will generate energy levels at least 10 times higher than CERN's, is expected to provide more direct evidence of the plasma.

"CERN produced a very short-lived state," Papavassiliou said. "The longer the state you create, the better you can observe it and the clearer your results." If CERN created a simmering pot of quark-gluon plasma, he said, Brookhaven's soup will reach a roiling boil.

The knowledge scientists gain from observing this soup "will help us learn what happened very, very early in the universe, a microsecond after the big bang," Pate said.

The PHENIX project is funded by the U.S. Department of Energy and RIKEN, the Japanese national research institute.

Photo is available at http://kiernan.nmsu.edu/newsphoto.
For a print, call (505) 646-3221.
PHOTO: detector.jpg
CUTLINE: Staff and students at the NMSU Advanced Manufacturing Center gather in and around the electronics support structure they built for the muon detector system of the PHENIX Experiment at Brookhaven National Laboratory in Long Island.

Karl Hill
March 27, 2000