Physicists across the globe rejoiced earlier this month at the announcement that the Large Hadron Collider—the gargantuan accelerator of sub-atomic particles meant to signal the dawning of a new age in high-energy physics—had successfully passed a beam of protons through its 17-mile tunnel.

But despite the euphoria of the “first beam” moment, the work has only begun for those involved with the Collider, both at the machine’s Geneva site—and here in Cambridge.

Four Harvard physics professors—John Huth, Joao Guimaraes da Costa, Masahiro Morii, and Melissa Franklin—remain intimately involved with the $8 billion collider, which stands as the most expensive scientific experiment ever attempted, and, when fully operational, may help bring to light particles and forces hitherto unseen.

The Harvard team has been primarily concerned with the construction and operation of the ATLAS detector, a cylindrical component of the collider engineered to gather data about the particles that emerge when the machine smashes protons together at energies of 14 trillion electron volts, recreating conditions that may have prevailed only a trillionth of a second after the universe’s inception.

Working closely with scientists from area institutions MIT, Boston University, Tufts, and Brandeis, Harvard saw construction of several key ATLAS parts—some as large as 72 feet across—at the spacious Oxford Street site of what, prior to its closing in 2002, was the University’s own particle accelerator. Finished pieces were then mailed overseas for assembly.

Since then, Harvard’s team of professors, along with a handful of graduate students and post-docs, have made the 10- to 12-hour trip between Cambridge and the collider’s home at the European Center for Nuclear Research (CERN), situated near the French-Swiss border.

“I spend a lot of time in a hardhat down inside of the thing, connecting cables, making sure things are done correctly, that kind of stuff,” said da Costa, currently on site at CERN.

Da Costa said he will be making periodic trips to Europe as he and his colleagues balance their Harvard teaching responsibilities with their collider work.

“Most of us are going back and forth,” Morii said. “We are trying to take turns, trying to keep the momentum going.”

Scientists hope that what happens in the collider’s tunnel, sunk some 300 feet below the ground, may help to shed light on the mystery of dark matter, the ultra-massive entity that many theoreticians believe to be an important component of the universe. Some also have said that extra dimensions may be revealed when the collider works itself up to speed.

Another goal of the collider is the discovery of the Higgs boson, the particle that is believed to give other particles their mass. The Higgs boson is the only particle from physics’ long-dominant Standard Model not to have been verified experimentally.

But for now, unveiling the Higgs particle will have to wait.

The overheating of a connection between two of the collider’s superconducting electromagnets, and the subsequent leakage of hydrogen into the collider tunnel resulted in the announcement on Saturday that the structure would have to be shut down for repairs. Further reports have indicated that the collider will not be run again until the spring.

The Harvard team does not seem discouraged by the delay, saying that the malfunction was expected and will give them valuable time to do further research on how to improve their detector equipment.

“Particle physics is always prone to minor technical glitches,” Morii said. “Those are more or less expected. We ere rather surprised that so far things came out so well. And it breaks and we say, ‘ah, now we’re talking.’

“Let’s say we lost three months of data,” da Costa said. “It’s not really three months because we’re going to improve things, and so, in reality, it’s not going to put us back from finding the Higgs by three months because we’re finding better ways to do things.”

Speaking by phone from Geneva, the alpine city that has suddenly become the capital of the physics community, da Costa paused.

“But it’s still kind of sad.”

—Staff writer Christian B. Flow can be reached at cflow@fas.harvard.edu.

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