The DZero Calorimeter.
Credit: Fermilab
WASHINGTON: U.S. physicists have been unable to confirm the findings of an atom-smasher experiment that was touted in April as possibly having discovered a new force of nature.
The initial findings caused a buzz in the scientific community and plenty of speculation over whether the elusive Higgs-Boson particle - which could explain why objects have mass - or another new elementary particle may have finally been detected.
But the DZero (D0) collaboration at the U.S. Department of Energy's Fermi National Accelerator Laboratory said the bump in the data found by its sister project, the Collider Detector at Fermilab (CDF), could not be replicated.
"We have looked among two hundred trillion particle collisions, and we don't see the excess reported by CDF," said DZero spokesman Dmitri Denisov.
How science works
Two months ago, CDF scientists reported an unexpected excess of proton-antiproton collisions that produce a W boson accompanied by two jets of particles. One possible explanation for the excess could be the existence of a new, unanticipated particle.
Now the DZero collaboration has finished an independent analysis that tests the CDF result, the scientists reporting in a paper to be published in Physical Review Letters that they did not find the same excess in the data.
Over the last 10 years, CDF and DZero have published more than 500 measurements of particle physics processes using two different particle detectors and independent analysis tools. The results agree more than 99% of the time, but there are rare occasions that the findings differ.
"This is exactly how science works," said DZero spokesman Stefan Soldner-Rembold. "Independent verification of any new observation is the key principle of scientific research. At the Tevatron, we have two experiments that, by design, can check each other."
Understanding the difference
The Tevatron was once the most powerful machine in the world for such purposes until 2008 when the Large Hadron Collider (LHC) became operational at the European Organisation for Nuclear Research, which goes by the acronym CERN.
The U.S. machine began its work in the mid 1980s, and is scheduled for shutdown later this year when its funding runs dry.
With the independent analyses having been completed, the difference between the two experiments' results must be understood and resolved. Fermilab Director Pier Oddone and the CDF and DZero collaborations have agreed to create a 'task force' that will coordinate a study of the two experiments' analyses.
