After decades of careful experiment, physicists say they have found the "strongest indication to date" to prove the existence of the Higgs boson -- a subatomic particle so important to the understanding of space, time and matter that the physicist Leon Lederman nicknamed it "the God particle."
The announcement today, based on experiments at the Department of Energy's Fermilab near Chicago and other institutions, is not the final word, but it's very close. And it comes just before a major meeting this week in Australia, where more findings will be announced from the giant underground particle accelerator at CERN, the great physics lab in the Alps on the French-Swiss border.
"This is one of the cornerstones of how we understand the universe," said Rob Roser, a Fermilab physicist, "and if it's not there, we have to go back and check our assumptions about how the universe exists."
Roser said he expected the CERN scientists to offer more evidence of the Higgs particle, though they will also be cautious. "The Higgs particle, if it's real, will show itself in different ways. We need for all of them to be consistent before we can say for sure we've seen it."
Fermilab has been home to an atom smasher called the Tevatron, which was shut down last year because CERN's Large Hadron Collider is more powerful. Scientists who used the Tevatron have been sifting through the masses of data they collected by sending subatomic particles crashing into each other at nearly the speed of light.
"During its life, the Tevatron must have produced thousands of Higgs particles, if they actually exist, and it's up to us to try to find them in the data we have collected," said Luciano Ristori, a physicist at Fermilab and the Italian National Institute for Nuclear Physics, in a statement. "We have developed sophisticated simulation and analysis programs to identify Higgs-like patterns. Still, it is easier to look for a friend's face in a sports stadium filled with 100,000 people than to search for a Higgs-like event among trillions of collisions."
The particle was first proposed in the 1960s by the English physicist Peter Higgs. The international effort to find it has taken decades, using tremendous amounts of energy to crash subatomic particles into each other in giant underground tracks, where they are steered by magnetic fields. Several different experiments have been done by independent teams to ensure accuracy.
Wednesday's report from scientists using CERN's Large Hadron Collider may sound similar to today's from Fermilab, but physicists will listen closely to the details.
"The LHC results that will be announced on July 4 will have much greater statistical significance and hence give us a much more detailed picture of what is really going on," said Mark Wise, a professor of high energy physics at the California Institute of Technology. "So in layman's terms: a hint from Fermilab and something more definitive to come on July 4."
Finding the Higgs particle would not be of practical value, at least not yet, but Roser argued that when the electron was first discovered in 1897, nobody guessed how it would lead to the high-tech, wired world we have today.
Physicists say the Higgs boson would help explain how we, and the rest of the universe, exist. It would explain why the matter created in the Big Bang has mass, and is able to coalesce. Without it, as CERN explained in a background paper, "the universe would be a very different place…. no ordinary matter as we know it, no chemistry, no biology, and no people."