New Clues in Higgs Boson Hunt
 The Fermilab accelerator complex accelerates protons and antiprotons close to the speed of light. The Tevatron produces about 10 million proton-antiproton collisions per second, maximizing the chance for discovery. Two experiments, CDF and DZero, search for new subatomic particles and forces unveiled by the collisions. Courtesy of Fermilab |
So far, the Higgs particle has eluded direct detection. However, recent experiments have zeroed in on the territory where the Higgs boson may be found. Sometimes referred to as the "God particle," it is a keystone in the theoretical framework known as the Standard Model of particles and their interactions, explaining why some elementary particles have mass and others do not.
Searches at the Large Electron Positron collider at the European laboratory CERN established that the Higgs boson must weigh more than 114 GeV/c.
2 Calculations of quantum effects involving the Higgs boson require its mass to be less than 185 GeV/c.
2 The latest analysis of data from the CDF and DZero collider experiments at the U.S. Department of Energy's Fermi National Accelerator Laboratory carve out a section in the middle of this range, excluding a mass between 160 and 170 GeV/c
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To increase their chances of finding the Higgs boson, the CDF and DZero scientists combine the results from their separate analyses, effectively doubling the data
 The CDF detector, about the size of a 3-story house, weighs about 6,000 tons. Its subsystems record the "debris" emerging from each high-energy proton-antiproton collision produced by the Tevatron. The detector records the path, energy and charge of the particles emerging from the collisions. This information can be used to look for particles emerging from the decay of a short-lived Higgs particle. Courtesy of Fermilab |
available. So far, CDF and DZero each have analyzed about three inverse femtobarns of collision data — the scientific unit that scientists use to count the number of collisions. Each experiment expects to receive a total of about 10 inverse femtobarns by the end of 2010.
The Higgs search result is among approximately 70 results that the CDF and DZero collaborations presented at the annual conference on Electroweak Physics and Unified Theories known as the Rencontres de Moriond, held March 7 to 14, 2009. In the past year, the two experiments have produced nearly 100 publications and about 50 Ph.D.s that have advanced particle physics at the energy frontier.
“Fermilab’s Tevatron collider typically produces about ten million collisions per second,” said DZero co-spokesperson Darien Wood, of Northeastern University.
 The DZero detector records particles emerging from high-energy proton-antiproton collisions produced by the Tevatron. Tracing the particles back to the center of the collision, scientists understand the subatomic processes that take place at the core of proton-antiproton collisions. Scientists search for the tiny fraction of collisions that might have produced a Higgs boson. Courtesy of Fermilab |
“The Standard Model predicts how many times a year we should expect to see the Higgs boson in our detector, and how often we should see particle signals that can mimic a Higgs. By refining our analysis techniques and by collecting more and more data, the true Higgs signal, if it exists, will sooner or later emerge.”
“A particle collision at the Tevatron collider can produce a Higgs boson in many different ways, and the Higgs particle can then decay into various particles,” said CDF co-spokesperson Rob Roser, of Fermilab. “Each experiment examines more and more possibilities. Combining all of them, we hope to see a first hint of the Higgs particle.”
"A cornerstone of NSF's support of particle physics is the search for the origin of mass, and this result takes us one step closer," said Physics Division Director Joe Dehmer, of the National Science Foundation.
The observation of the Higgs particle is also one of the goals of the Large Hadron Collider experiments at