ATLAS, set to begin in 2007, is the next big thing in the
highly collaborative world of subatomic physics research.
ONE DAY NEXT YEAR, PAIRS OF PROTONS will begin zipping in opposing directions around a 27-km circular tunnel beneath the French-Swiss border. Propelled to nearly the speed of light by a series of super-conducting magnets, those tiny particles will collide head-on. The microcosmic wreckage that they produce may take us crucial steps closer to explaining the fundamental how’s and why’s of the physical laws of nature.
From miniature black holes to exotic particles like those that occurred fractions of seconds after the big bang, the ATLAS experiment is designed to probe some of the most fundamental yet elusive answers to questions about nature and energy and the origin of the universe: Why do particles have mass? How can the presence of “dark matter” be explained? Is there more than meets the eye, phenomena that haven’t even been considered yet?
More than a decade in planning, entire research careers have been dedicated to this, the next big thing in the minute world of high-energy physics.
ATLAS involves an international league of some 2,000 particle physicists, all doctorate-holders, and all independent thinkers yet team-focused with a single purpose in mind. Sociologists have done studies on how it is that such a diverse group from 34 countries and 160 institutions is able to agree on anything, let alone the direction of a massive scientific enterprise.
“It’s like an army of generals—it’s not perfect but we’re moving forward,” Prof. Michel Lefebvre noted recently in his office on the second floor of the Elliott Building, where his old basketball team photos line the wall above an academic’s typical nest of research journals, papers and filing cabinets.
It’s what Lefebvre calls the “cross-pollination, culturally and scientifically” that those involved in the collaboration are really proud of, although it’s not without its challenges. It’s an effort to work effectively with research colleagues spread across the globe. Phone and Web conferencing can be efficient but they’re not a substitute for face-to-face meetings. And while much of the engineering and construction of the LHC and ATLAS is complete, there remains a massive amount of computer software code to be written that is “pushing the envelope of complexity with hundreds of people writing different parts at the same time,” says Lefebvre. “Imagine writing a book with 50 different people writing each chapter.”
Perhaps no one else in Canada’s physics community has been as closely involved in ATLAS (the largest particle physics experiment yet) as Lefebvre. Since arriving at the university in 1991, he has been at the forefront of the country’s involvement in ATLAS-Canada, serving as its founding spokesperson. His excitement and anticipation for what ATLAS holds becomes immediately apparent. After years of planning, after countless flights back and forth to Geneva, the weekly videoconferences and the endless writing of computer code, ATLAS is nearly ready to begin and Michel Lefebvre is utterly enthused. He is his own force of nature, a diminutive scientist on the verge of seeing years of preparation finally become reality, promising not just a whole new chapter but volumes upon volumes of raw research material. Observers speculate that at least two Nobel Prize-worthy discoveries will come out of the smashed protons of ATLAS.
The Standard Model summarizes current knowledge of particle physics. It includes the theory of strong interactions and the theory of weak and electromagnetic interactions. What it doesn’t explain is how particles get their mass. “That needs to be squared away,” says Professor Emeritus Alan Astbury. “There is a Higgs mechanism, a Higgs particle. So what you might call the Holy Grail is to find the Higgs, if it exists—and that’s a very big demand on a detector.”
Astbury looks back on his 50 years in physics research and thinks of all of the advances. Yet, it can seem that the more we know, the less we know. “Things have changed in that time. We were looking for the constituents that really make up matter, you and me and this table and everything around it. But as we’ve understood more and more about the universe, this kind of matter seems to be only a small fraction of what there is—five or 10 per cent. It’s just possible, at the LHC, that the very exciting discovery that may be made is a new form of matter, which accounts for a significant amount of what they call the dark matter that is out there. This is not predicted, and it would be an extremely important discovery if it was made, but it certainly doesn’t have a probability of zero.”
It’s that promise of the unknown that, when it comes down to it, seems to drive the enthusiasm for the ATLAS project that leading researchers like Michel Lefebvre exude, even in the face of another 10 or 15 years of data collection and analysis. “I hope we’re going to be so confused by what we find that it’s going to keep us busy for a very long time. There are no guarantees (of what we’ll find). All you can do is go have a look.”
When Protons Collide
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Grid Computing | The Racetrack
and the Camera