Scientists at U.S. Lab Detect Hints of Elusive Particle

Analyzing data from some 500 trillion sub-atomic particle collisions designed to emulate conditions right after the Big Bang when the universe was formed, scientists at Fermilab outside Chicago produced some 1,000 Higgs particles over a decade of work.

"Unfortunately, this hint is not significant enough to conclude that the Higgs boson exists," said Rob Roser, a physicist at Fermilab, near Chicago, in explaining the findings being presented on Wednesday at a conference in La Thuille, Italy.

The image scientists have of the short-lived Higgs particles, which almost immediately decay into other particles, is still slightly "fuzzy," Roser said.

The probability that what physicists detected is not a Higgs boson and is instead a statistical fluke was 1 in 250, which is near the threshold of 1 in 740 that physics has set to establish proof of a sub-atomic particle's existence.

The hunt for the Higgs boson is significant because it would show the existence of an invisible field thought to permeate the entire universe. The Higgs field was posited in the 1960s by British scientist Peter Higgs as the way that matter obtained mass after the universe was created during the Big Bang.

According to the theory, it was the agent that made the stars, planets and life possible by giving mass to most elementary particles. Some gave it the nickname the "God particle."

Discovery of the Higgs would also complete Einstein's Standard Model of Physics. If it does not exist, scientists would have to search elsewhere for how particles gained mass and why they are not merely shooting aimlessly through the universe.

The weight of Higgs particles found at Fermilab was consistent with those detected at the more powerful particle accelerator, the Large Hadron Collider, at the CERN research center near Geneva, Switzerland.

CERN, the European Organization for Nuclear Research, is hot on the trail of the Higgs boson and hopes to gain proof of the particle before its accelerator temporarily shuts down at the end of 2012 for an upgrade.

Before Fermilab's four-mile (6.3-km) -long Tevatron was closed for good in September 2011 and the particle accelerator baton handed to CERN, scientists pushed the collider to produce as many sub-atomic collisions as possible.

The two circular accelerators operate differently, Roser said. Fermilab's accelerator fired protons at antiprotons, while CERN's 16.7-mile (27-km) -long accelerator creates collisions between two beams of protons.

An analogy posed by physicist Gregorio Bernardi in a statement released by Fermilab was of two people taking a picture of a child in a park from different vantage points.

"One picture may show a child that is blocked from the other's view by a tree. Both pictures may show the child but only one can resolve the child's features. You need to combine both viewpoints to get a true picture of who is in the park," he said.

Physicists from around the world are at work at both laboratories, with hundreds still laboring at Fermilab analyzing the data from its experiments.

"We've used up most of our data" at Fermilab, Roser said. "We'll do a few more experiments and try to have a final answer in June."