..the Race Is on for the ‘God Particle’

By DENNIS OVERBYE / from the New York Times

...As the analyses proceed and the Tevatron hums its trillion-electron-volt tune, this is a summer of rumors, hope and hype. Whatever the outcome for this particular Higgs rumor, the buzz about it illuminates the galloping expectations, tensions and rivalries roiling physicists as they await the inauguration next summer of the Large Hadron Collider, a giant accelerator at CERN, the nuclear laboratory outside Geneva expressly designed to find the Higgs particle and explore new realms of nature.

The excitement has been ratcheted up by the speed and ubiquity of information on the Internet...

Confirming the rumored bump would confirm a profound conjecture about how nature works, cementing into place the last missing piece of the so-called Standard Model and perhaps pointing the way to a deeper theory that could answer questions the current model leaves open — such as why the universe is full of matter but not antimatter — a New World of physics...

Unfortunately, the model does not say how heavy the Higgs boson itself — the quantum personification of this field — should be. And so physicists have to search for it the old-fashioned train-wreck way, by smashing subatomic particles together to create primordial fireballs and then seeing what materializes out.

The Higgs, if formed, would decay into smaller jets of quarks or other particles, depending on its mass. The heavier it is, the more kinds of particles it can decay into. These would be recorded and counted by the detectors.

Unfortunately, as Dr. Weinberg pointed out, ordinary collisions also produce showers of the same particles coming out, and so the game has changed.

Once upon a time, physicists would look for what they called “a gold-plated event.”

“You looked at a bubble chamber and saw tracks and decays,” Dr. Weinberg recalled. “You knew what you were seeing: ‘Aha! This is the omega minus,’ ” referring to a famous particle whose discovery clinched the case for quarks in 1964.
Now, he explained, high-energy physics is all statistical. Out of 100,000 events, are a few more at various energies statistically significant? The job, he said, is to build up statistics to the point where a definite statement can be made...

The first and most famous bump in the Higgs race happened at CERN’s Large Electron-Positron Collider, or L.E.P., just before it was shut down in 2000 to make way for the new collider. It suggested that the Higgs might be waiting to be discovered just above 114 billion electron volts, in the energy-mass units physicists prefer to use...

Rather than undercutting the rationale for CERN’s collider, finding the Higgs at Fermilab would only whet the world’s appetite for the bigger machine, physicists on both sides of the Atlantic said. The best Fermilab can hope for is a glimpse of the Higgs, and probably a hint of new mysteries and discoveries to be made...

If it is a Higgs, theorists say, it is probably not the one prescribed by the Standard Model, which would not be produced plentifully enough to be seen yet.

The leading alternative is that it would be one of five Higgs bosons predicted by a theory called supersymmetry, which theorists have been yearning for as the next step toward a more all-embracing, unified theory of nature. One bonus of supersymmetry is that it predicts the existence of more, yet undiscovered elementary particles, one of which might be the mysterious dark matter that binds galaxies together in the universe. All this would fall into the lap of the Large Hadron Collider scientists, if it exists, which is one reason the CERN physicists will be happy no matter what the outcome....

“I don’t know if we pinned down nature, or if nature has pinned us down, but there are many corners you can’t get into anymore,” Dr. Lykken said.