Tuesday, December 13, 2011

New data said to narrow hunt for ‘God’ particle

Guido Tonelli (R), CMS experiment spokesperson, gestures next to Rolf Heuer (C), CERN Director General, and Fabiola Gianotti, ATLAS experiment spokesperson, during a news conference at the CERN (European Organisation for Nuclear Research) in Meyrin, near Geneva. -Reuters Photo

GENEVA: Scientists hunting for an elusive sub-atomic 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 building block of the universe. The researchers added that they hope to reach a conclusion on whether the particle exists by next year.
The latest data show that the mass of the Higgs boson, popularly referred to as the ”God particle”, probably falls within a particular range, in the lower end of the spectrum that can be produced by smashing protons together in the massive machine being used to track it down, 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 the Higgs boson is around 124 to 126 billion electron volts, the teams said.
The revelations Tuesday were heavily anticipated by thousands of researchers who hope that the particle, if it exists, can help explain many mysteries of the universe. British physicist Peter Higgs and others theorized the particle’s existence more than 40 years ago to explain why subatomic 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.
Fabiola Gianotti, an Italian physicist who heads the team running the so-called 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.
Afterward, Guido Tonelli, lead physicist for the team running what’s called the 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.
Rolf Heuer, director of the European particle physics laboratory near Geneva, said ”the window for the Higgs mass gets smaller and smaller.”
”But be careful it’s intriguing hints,” he said. ”We have not found it yet, we have not excluded it yet.”
The Higgs boson is hard to find not because it is especially tiny, but rather because it is hard to create, said physicist Howard Gordon of the Brookhaven National Laboratory in Upton, N.Y., who works with the ATLAS experiment.
Physicists smash protons together at very high energy, and only a minority of collisions will create a Higgs boson. The more energy involved, the higher the fraction of collisions that will make a Higgs.
Frank Wilczek, a Nobel laureate and physics professor at the Massachusetts Institute of Technology, said finding the Higgs boson would tie up a loose end of the so-called standard model of physics, which requires a Higgs-like particle exist.
Proving the Higgs exists would be ”a vindication of the equations we’ve been using all these years,” he said. ”Since the equations have worked so brilliantly now for decades, it’s really nice to dot the i’s and cross the t’s,” he said.
In addition, if the mass of the Higgs is within a certain range, that would support some other theories that go beyond and improve the standard model, he said. Those theories predict the existence of still other particles to be found. That would mean the Large Hadron Collider ”will have another wave of brilliant discoveries in the future,” Wilczek said. The mass range reported Tuesday is ”perfect” to meet that requirement, he said.
”Because it fits together so beautifully with everything else we know … I’m certainly inclined to believe it,” he said. He called Tuesday’s presentations ”awesome … just beautiful work.”

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