March 12, 2008

Understanding how the universe is made
SMU physicists help build CERN's massive particle detector

SMU scientists are one step closer to understanding some of the basic forces that shape the universe with the recent installation of the 7,000-ton subatomic particle detector they helped build for the Large Hadron Collider in Geneva, Switzerland.

Ryszard Stroynowski

“This is the biggest science project ever, as far as I know, and probably the most complex,” said SMU Physics Department Chairman Ryszard Stroynowski. “It’s also on the very leading edge of science. I think it provides opportunities for SMU students and researchers to be part of great discoveries, and those types of things don’t come more than a couple times in a lifetime.”

Lowering the final piece of the Atlas particle detector into an underground chamber on Feb. 29 effectively ended the construction phase of the largest particle accelerator in the world. The federal government provided funds for U.S. physicists to participate in the CERN (European Center for Nuclear Research) international project after Congress cancelled funding for the Superconducting Super Collider near Waxahachie (outside Dallas) in 1993.

The Large Hadron Collider is a 27-kilometer enclosed, circular racetrack that will use a magnetic field to propel high energy protons into each other when it begins operating this summer. Those collisions will release even smaller pieces of matter, and the Atlas particle detector will help measure the tracks they leave. This huge, international project is directed at finding the Higgs boson, the subatomic “God particle” that physicists believe could help explain the origin of the universe.

Here’s the theory behind the Higgs boson: All particles had no mass just after the “Big Bang.” As the Universe cooled and the temperature fell below a critical value, an invisible force field composed of subatomic particles called the “Higgs boson” developed throughout the cosmos. Particles that interact with the field gain mass and particles that never interact have no mass. But the theory remains unproven because no one has ever seen the Higgs boson at work.

Atlas particle detector is lowered into position.

Stroynowksi is U.S. Coordinator for the Liquid Argon Calorimeter at the heart of the Atlas particle detector, which will track the high-energy debris left by the collision of particles. Of the almost 2,100 participants in the ATLAS collaboration, about 420 are U.S. physicists, engineers, and graduate students from 38 universities and four national laboratories, and these U.S. collaborators are supported by the U.S. Department of Energy and the National Science Foundation (NSF).

SMU Physics Department faculty members Robert Kehoe and Jingbo Ye have worked with Stroynowski on the project, as well as Fredrick Olness, who helped with theoretical calculations. Postdoctoral students Julia Hoffman, David Joffe, Daniel Goldin, Peter Renkel and Haleh Hadavand are part of the team, as well as graduate students Ana Firan, Renat Ishmukhametov, Kamile Dindar, Azzedin Kasmi, Ryan Rios, Rozmin Daya, Yuri Ilchenko, Zihua Liang, Travis Howe and Pavel Zarzhitsky.

“We’re proud of the teams involved in this international scientific endeavor -- one of the largest collaborative efforts ever attempted in the physical sciences,” said Dennis Kovar, acting associate director for High Energy Physics in the U.S. Department of Energy’s Office of Science. “This technical landmark brings us a huge step closer to unveiling a new level of understanding of our universe.”

“The experiment will start detecting collisions when the accelerator starts working, and then we will have to process the data and look at it for years to come,” Stroynowski said. “The real fun starts at the end of this year.”

# # #