Originally created 02/11/00

European lab finds 'compelling' evidence closer to Big Bang



GENEVA -- A series of atom-smashing experiments has for the first time produced "compelling" evidence that the smallest particles floated freely a split second after the creation of the universe, scientists announced today.

The discovery is a breakthrough in the attempt to study the exact moment of the Big Bang, the explosion in which scientists believe the universe was born, and it is a first step in studying states of matter as yet unobserved.

In the experiments, the scientists were able to indirectly observe the "primordial soup" of quarks and gluons spewed out in the first few microseconds -- or millionths of a second -- after the explosion.

The discovery verifies an essential part of the Big Bang theory, that the quarks and gluons existed in a free state before the intense heat cooled slightly and they joined to form larger particles, such as protons and neutrons.

Quarks are the smallest known particle. Before the CERN experiments, science had seen quarks and gluons only in the "trapped" state they have existed in since three minutes after the Big Bang.

"We have recreated matter in a state we have never seen before, at energy densities 20 times higher than that inside the atomic nucleus," said a statement by CERN, also known as the European Laboratory for Particle Physics. "The same conditions have only existed in the first few microseconds after the Big Bang."

CERN spokesman Neil Calder said the "important scientific breakthrough" came in a series of experiments by 350 scientists from around the world, beginning in 1994.

"We now have evidence of a new state of matter where quarks and gluons are not confined," said professor Luciano Maiani, CERN's director-general.

Calder said: "If the Big Bang theory is correct, if the universe started the way which we believe it did, then at some stage these quarks must have been floating around in a kind of soup before they got caged inside other particles."

The CERN statement said that the evidence was "compelling enough to say that we have formed a new state of matter."

The evidence, however, is indirect because it stems from the measurement of particles that have already returned to their confined state, it said.

Even though CERN hasn't been able to study the free quarks and gluons, they know they created them because the particles "retain enough memory" of that state -- "like the grin of the Cheshire cat in Alice in Wonderland which remains even after the cat has disappeared."

It will be up to the new Relativistic Heavy Ion Collider, or RHIC, at Brookhaven National Laboratory on New York's Long Island to enable scientists to examine the so-called "quark-gluon plasma," Maiani said.

Edward Suryak, a professor at Stoneybrook State University, Long Island, said the CERN work was a first step but that the Brookhaven lab will create significantly larger energy that will let scientists study the quark phenomenon much more closely.

The plasma created at CERN "appears for a short time" only, he said in a telephone interview.

Scientists have long expected to find this super hot "primordial soup" according to the theory that the universe was created in a gigantic explosion.

But their accelerators that smash subatomic particles into each other have been too weak to create the extremely hot state where the quarks and gluons floated freely.

"All around the world physicists have been trying to recreate this soup, and this we have now cooked up at CERN," Calder said.

James Gillies, a CERN physicist, told The Associated Press that CERN's accelerators "had just enough energy to be able to create the stuff, but 'just enough' isn't enough to be able to study its properties in great detail."

"It's very good news for RHIC, because they will be able to make it very easily and study it in great detail," Gillies said.

He noted that many of the scientists who have been working at CERN will also work at Brookhaven -- and return to Geneva in 2005 when CERN will have an even more powerful accelerator.