More than 300 feet beneath the suburbs and sunflower fields at the French-Swiss border lies a high-tech beast that may signal the doom of Fermilab.
The particle accelerator called the Large Hadron Collider is coming to life in tunnels and caverns that crackle with the anticipation of an enterprise at the leading edge of physics. For 40 years, that vaunted role belonged to Fermi National Accelerator Laboratory, bringing the Chicago area civic prestige and unique academic clout, but that’s about to change.
Everything about the European facility dwarfs its counterpart physics lab in Batavia. Right now Fermilab houses the world’s most powerful particle accelerator, smashing together bits of matter and antimatter to unlock the secrets of nature. But the LHC will be seven times more powerful when it begins operation next year, making the Illinois device almost instantly obsolete.
The time pressure has launched Fermilab on a flat-out sprint to prove the existence of a tiny, theoretical particle called the Higgs boson, a linchpin of prevailing ideas about how the universe is put together. If experts are right, the Higgs gives everything its mass, its heft — from the subatomic mist to people, buildings and stars.
Internet rumormongers claimed earlier this year that the Batavia lab already had spotted signs of the prized particle. Project leaders say any speculation is premature, though they could get an answer within the next year.
Their quest marks the poignant closing of an era, for Fermilab and for physics in America. Once the lab’s main accelerator finishes its work and shuts down in 2009, it will be the first time since scientists started exploring the subatomic “energy frontier” that no American facility will be leading the way.
“For us it’s a painful experience,” said Fermilab Director Pier Oddone. “We are at the center of the physics universe right now. And when the LHC opens we won’t be.”
Some smaller experiments will continue at Fermilab, and the lab hopes to land new projects in the next decade. But the facility’s unmatched intellectual energy will fade, for a few years if not longer. Scientists who once made pilgrimages to Fermilab’s mighty collider already have started new work in Switzerland.
The value of such labs transcends national pride. They are the world’s most powerful microscopes, able to crack open the tiniest bits of matter and unveil the strange realm inside. That requires small cities of engineers and theorists working at the limit of what advanced materials can withstand and science can predict.
Some physicists call the labs “miracle factories.”
The heart of the $10 billion effort on the outskirts of Geneva is a 17-mile underground ring where particles will flit between France and Switzerland at nearly the speed of light. Workers have festooned the subterranean border with national flags and cheeky graffiti.
Four times larger in circumference than the main ring at Fermilab, the LHC will accelerate protons using 1,200 superconducting magnets cooled by the world’s largest supply of liquid helium. The accelerator should yield more than 100 times the number of subatomic collisions seen at the Tevatron, the name of Fermilab’s big ring.
Scientists expect the collider to discern the Higgs particle within a year or two of starting up — compared with the Tevatron, which is only now within striking distance after six years of operating at full capacity.
“It’s just going to blow the Tevatron out of the water,” said John Ellis, a theoretical physicist at CERN, the Geneva-based physics organization that runs the new collider.
No one appreciates the challenge better than Jacobo Konigsberg, a leader of the Higgs search at Fermilab whose cell phone belts out the theme from “Mission Impossible.”
“There’s no down time for me now,” said Konigsberg, a Mexican by birth who gave up his soccer hobby in part to accommodate the increasing workload. “Even though the shadow of the LHC looms, we’re relentless in our pursuit.”
To find the Higgs, Konigsberg and his colleagues must pluck a ghostly needle from an immense haystack of particle haze.
Theorists and journalists often talk of the Higgs boson as a fugitive with a known name and address. In truth the particle is a cipher, a trumped-up placeholder that researchers proposed only because modern physics would not make sense without it.
“It’s a black-box description of something we know is present, but we don’t know what it is,” said Fermilab theorist Chris Hill. The
Higgs holds an enigmatic spot in the Standard Model, the 30-year-old theory that predicts all of the known fundamental particles — electrons, protons, quarks, muons and even stranger-sounding things. Every other part of the model has fallen into place, with the Higgs the last puzzle piece.
In the model’s purest form, nothing would have mass. Physicists speak almost wistfully of the notion, saying the Standard Model’s equations are elegant, like a symmetrical sphere — so long as everything is massless. But mass does exist, and to accommodate that awkward fact scientists dreamed up something called the Higgs field, named after British physicist Peter Higgs.
The Higgs field permeates the vacuum of the universe, physicists believe. It is an invisible ocean in which we swim, and each type of particle interacts with the “water” of the Higgs field differently.
“Massless particles are like tiny minnows — the water doesn’t slow them down at all,” Hill said. The photons that carry light are one example of a massless particle. “Then you get really massive things like the top quark, which is just a giant jellyfish that lumbers around,” he said.
The job of high-energy colliders like the Tevatron and the LHC is to stir up frothy bubbles in the subatomic sea. Collisions pump energy into the Higgs field, which is thought to be made of normally undetectable Higgs particles. The extra energy can shake loose a Higgs particle, like a tiny drop flying from a cresting ocean wave.
Roiling up that ocean takes special kinds of collisions. The Tevatron smashes together protons and antiprotons, while the LHC smacks protons into each other. The particles race along the great “O” of the accelerators within vacuum-sealed metal pipes at nearly the speed of light. The collisions occur at preordained points where the metal pipe is surrounded by vast, intricate detectors that track the shower of debris from the impact and how much energy the fragments carry.
The Higgs could pop out somewhere in that mess of atomic shards, but it’s hard to spot. A Higgs would decay into other particles within a tiny fraction of one-billionth of a second after it appeared. So rather than look for the Higgs itself, physicists will search for a trail of two quarks, the particles left over once the Higgs decays.
But spotting one trail of quarks isn’t enough to deduce that they came from a Higgs, because ordinary processes can make similar quark duos. Physicists need to find a surplus of quark decays, so many that only the Higgs could account for them. That requires using statistics to search through billions of collisions for a spike.
If the process is something of a crapshoot, the LHC is the ultimate casino, capable of producing 1 billion collisions a second.
The big rooms where the Europeans will try to spot the Higgs are hulking cathedrals to technology; the detector called ATLAS is crowned with eight superconducting loops weighing 100 tons each. The magnets curve the path of fragments from a collision to help experts calculate their momentum.
“We are going to explore a completely new energy scale,” said Fabiola Gianotti, a deputy director of the ATLAS project, as she toured the nearly completed detector.
For all the effort there and in Batavia, no one is sure either accelerator will find the Higgs.
Such a letdown, considered unlikely but not impossible, would overturn the Standard Model. That prospect is alluring for theoreticians such as Ellis, because it would require a totally new vision of the subatomic world. On the other hand, “it might not be so funny to explain to the politicians who have funded the LHC mainly to discover this particle,” Ellis wrote recently in the journal Nature.
Whatever happens, most experts think both the Tevatron and the LHC stand a good chance of making major advances. The accelerators could find traces of dark matter, the mysterious substance that seems to make up 25 percent of the universe. They could also find support for supersymmetry, a theory that predicts each fundamental particle has an unseen counterpart — “ballet partners,” Ellis calls them. “I think either we’ll see the Higgs boson or we’ll get some very strange phenomena,” Gianotti said.
The LHC’s ascendance will mean a fallow period for Fermilab, at least until the lab can land a new mega-project. Leaders hope to build a 20-mile long device called the International Linear Collider, but because that project would build on findings from the LHC, its design won’t be known until the European collider starts making discoveries — which is at least several years away.
In the meantime, Americans will play a key role at the European facility that goes far beyond the half-billion dollars the U.S. has poured into the project.
More than 1,000 American engineers and physicists are collaborators at the LHC — the biggest science contingent of any single country. It’s also comparable to the number of Americans who do science at Fermilab now. A huge chunk of Fermilab’s scientists are switching over to work on the LHC’s experiments.
In that sense the future of American physics lies not in the Chicago suburbs, but in the shadow of the Swiss mountains.
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IN THE WEB EDITION
Take a video tour of the mammoth Large Hadron Collider in Switzerland that threatens the lead of Fermilab in Batavia at chicagotribune.com/collider
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jmanier@tribune.com
