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U of M physics professor Roger Rusack’s contribution to the Higgs particle discovery is his electromagnetic calorimeter, which measures the energies of photons.

David Joles, Star Tribune

U prof a player in Higgs particle puzzle

  • Article by: JENNA ROSS
  • Star Tribune
  • July 6, 2012 - 10:46 PM

A universal discovery. An international team. A Minnesota scientist.

Roger Rusack, a University of Minnesota physics professor, is one of dozens of U scientists and students who have helped with a grand experiment that this week announced evidence of a new subatomic particle.

Rusack, a longtime professor in the U's School of Physics and Astronomy, has been a part of the search for the elusive Higgs particle from the experiment's beginning, two decades ago. He helped design, develop and tweak a critical particle detector within the massive, 17-mile-long Large Hadron Collider in Geneva, Switzerland, the world's most powerful particle accelerator. His contribution, the electromagnetic calorimeter, measures the energies of photons.

He described the Higgs particle as "present everywhere," forming a kind of force field that gives all matter in the universe mass. So the idea was that if this field exists, you should be able to see it. Put in enough energy in the collider, scientists thought, and "this particle would pop out," Rusack said.

It did, and this week, the world noticed.

There and back again

He spent two full years at CERN, the European Organization for Nuclear Research, still travels there regularly and was in the facility a few weeks ago when he thought, "Boy, we really have it." Yet he was careful to leave the facility with a frown.

"'They said, 'The BBC is outside. Look glum,'" he said, laughing.

But once the work wrapped up, Rusack traveled back to his family in Minnesota. So he wasn't one of the hundreds of scientists packed into the CERN auditorium for the announcement early Wednesday morning. "I was listening to it online at 2 a.m.," Rusack said.

He, like other physicists, cringes when the Higgs boson gets called "the God particle."

"It's awful. Dreadful," Rusack said. "The implication is that out of this, everything comes, which is plainly wrong."

But he appreciates the international attention being given to this "wonderfully complicated" collider, the scientists' findings and physics generally. In an airport last month, Rusack got to talking with some German students about what he does. They responded: "Oh, you're looking for the Higgs boson?"

"They weren't scientists, but they knew about it," he said. "I think that's just wonderful."

More to tell his U students

This discovery won't change what Rusack teaches in his introductory college physics course. But it will affect more advanced courses on particle physics. Rusack said all his classes love hearing about the particle accelerator.

"This is what the field is about," he said, "understanding how the universe fundamentally was put together."

He said that 63 University of Minnesota professors, graduate students, research associates, technicians and undergraduates have been registered at CERN since the experiment began. Almost half of them are currently involved. Thousands of scientists from 41 countries are actively involved with the project.

But they all speak "the same mathematical language," Rusack said. "It gives me a lot of hope for the rest of us."

Next, Rusack will help lead the experiment's next phase, upgrading the collider to "even higher brightness," illuminating further mysteries.

Jenna Ross • 612-673-7168

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