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Why do objects have mass? The elusive Higgs boson could hold the key.

Scientists at CERN say that they are closing in on demonstrating the existence of the elusive Higgs boson – the theoretical subatomic particle that could explain why particles have mass.

By John HeilprinAssociated Press / December 13, 2011

Fabiola Gianotti (l.), ATLAS experiment spokesperson, speaks next to Guido Tonelli (r.), CMS experiment spokesperson, and Rolf Heuer, CERN Director General, during a news conference at the CERN (European Organization for Nuclear Research) in Meyrin, near Geneva Tuesday.

Denis Balibouse/Reuters



Scientists hunting for an elusive subatomic particle say they've found "intriguing hints" — but not definitive proof — that it exists, narrowing down the search for what is believed to be a basic component of the universe. The researchers added that they hope to reach a conclusion on whether the particle exists by next year.

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The latest data show that the mass of the Higgs boson — popularly referred to as the "God particle" — probably falls in the lower end of the spectrum of mass that can be produced by smashing protons together in the huge Large Hadron Collider, researchers from two independent teams said Tuesday.

The two teams said their data indicates the particle itself may have a mass of between roughly 114 and 130 billion electron volts. One billion electron volts is roughly the mass of a proton. The most likely mass of theHiggs boson is around 124 to 126 billion electron volts, the teams said.

Until Tuesday, the most likely mass was seen as between 114 and 141 billion electron volts. There is still a small possibility that the Higgs could be much more massive and found above 476 billion electron volts, physicists said.

The revelations Tuesday were heavily anticipated by thousands of researchers who hope that the particle, if it exists, can help explain why there is mass in the universe. British physicist Peter Higgs and others theorized the particle's existence more than 40 years ago to explain why fundamental particles — building blocks of the universe — have mass.

Both of the research teams work at CERN, the European Organization for Nuclear Research near Geneva. CERN runs the $10-billion Large Hadron Collider under the Swiss-French border, a 17-mile (27-kilometer) tunnel where high energy beams of protons are sent crashing into each other at incredible speeds.

Collisions between protons smashed in the collider produce energy that in turn creates other particles. On rare occasions, this energy could produce the Higgs particle — if it exists.

Fabiola Gianotti, an Italian physicist who heads the team running the ATLAS experiment, said "the hottest region" is in lower mass ranges of the collider. She said there are indications of the Higgs' existence and that with enough data it could be unambiguously discovered or ruled out next year.

The results rule out several mass or energy ranges for the Higgs with a high degree of confidence, Gianotti said.

"The most important result is that we have been able to restrict the most likely mass region to a very narrow range," she said.

Afterward, Guido Tonelli, lead physicist for the team running the separate CMS experiment, outlined findings similar to those of the ATLAS team, saying the particle is most likely found "in the low mass region" among the spectrum of possible Higgs masses.

CERN's director-general, Rolf Heuer, said "the window for the Higgs mass gets smaller and smaller."

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