More scientists are getting closer in the search for the "god particle" of physics that would help explain the fundamentals of the universe, but they haven't found it yet.
Two teams of physicists hunting for the Higgs boson in results from a now-closed American accelerator have come up with similar findings to those announced late last year by researchers at the more powerful Large Hadron Collider in Europe.
While the scientists using the two accelerators have not found the elusive subatomic particle, which is key to understanding why matter has mass, they both have narrowed the area where it can be found, if it exists. And they know where it isn't.
The Higgs boson and the Standard Model
The Higgs boson — nicknamed the "god particle" by 1988 Nobel Prize winner Leon Lederman — is a subatomic particle that plays a key role in the Standard Model of physics that describes the understanding of all elementary particles and how they interact.
The Standard Model of Physics includes common particles like electrons and photons along with less familiar ones like muons. Among them, the Higgs boson is the only one that remains undetected in experiments. However, it is extremely important because it allows particles to have mass.
The Higgs boson and its mechanism for imparting mass to other particles were first proposed by British physicist Peter Higgs 40 years ago.
The Large Hadron Collider is expected to help scientists find the Higgs boson, if it exists, because it allows them to observe extremely high energy collisions similar to those during the Big Bang. Those could in turn produce the previously undetected particle.
If a Higgs boson that behaves according to the Standard Model exists, Higgs's theory would be confirmed. However, if the Higgs boson doesn't behave according to predictions or is not detected at all, that would open the door to completely new physics outside the Standard Model and our current understanding of nature.
Work done in the Tevatron collider at the Fermi National Lab near Chicago provides important independent confirmation of the getting-closer announcement last year by CERN, the European Organization for Nuclear Research near Geneva, researchers said. The results from work by more than 800 scientists were to be announced in Italy on Wednesday.
"Globally the world is starting to see a consistent picture," said Fermi physicist Rob Roser, a spokesman for one team. "I don't think there's any place for the Higgs to hide. We'll know the answer one way or another by the end of 2012."
Roser said just because they have seen hints of the Higgs, it's not enough. "I'm not even willing to bet your house on it, let alone mine," he said Tuesday.
At Fermi, two teams independently used the accelerator in different ways. Two other teams in Europe used the Large Hadron Collider. Fermi's Tevatron collides protons and antiprotons together, while CERN smashes protons together. That means four different groups using different techniques and equipment have come to the same general conclusion.
Still, that's not certain enough for scientists to even call it evidence, Roser said.
While the results from Fermi's collider aren't as precise as CERN's, they are important because they give the European results more credence, Harvard University physicist Gary Feldman said.
The Tevatron closed in September, so it is likely that the final discovery of the Higgs will be in Europe, Roser said.
The Higgs, first hypothesized 40 years ago, is important to physics because it is crucial to the standard model theory that helps explain the six particles that make up the universe, Roser and Feldman said. Without it, there is no explanation for why the particles have mass.
"It would be a triumph of the theory to actually see that it happens," Feldman said.