Physicists play leading role in international experiments


Discovering the fundamental laws of nature from the high-speed collisions of subatomic particles is potentially the most far-reaching scientific research in the world, and physicists at The University of Texas at Arlington are at the forefront of this exploration.

The High Energy Physics group conducts experiments at the highest-energy accelerators in the world—Fermilab in Chicago and the European supercollider at CERN in Geneva, Switzerland. The research examines essential questions: What are the smallest particles? Which are the basic forces? Where does mass come from? Why is there so little antimatter in the universe?

“Investment in fundamental research has always paid huge dividends for the economy,” says physics Professor Andrew White. “It is essential that we keep building our knowledge base to sustain this process and to satisfy our natural curiosity about the way the world works.”

UT Arlington has been selected as one of three sites for a Tier 2 grid computing center for the ATLAS experiment at CERN.  Two pairs of universities—the University of Chicago and Indiana University, and Boston University and Harvard University—will host the other centers.

Funded by a multimillion-dollar grant from the National Science Foundation, the UT Arlington center includes participation by Oklahoma University,  the University of New Mexico and Langston University. UT Arlington serves as the lead institution for the project, and physics Professor Kaushik De is the principal investigator.

Dr. De and other physicists recently took part in an international project for the ATLAS experiment to link tens of thousands of computers to create one of the largest data grids in the world. Computers from more than 50 countries and hundreds of universities and laboratories worked together to solve fundamental problems in physics.

De led U.S. participation in this groundbreaking exercise and developed the Windmill software that supervised all the computers.

“We have played a leadership role in adopting grid computing technology for use in ATLAS,” he said. “The Windmill software supervised the task of sending the computing work to the sites and collecting and verifying the results. More than 100 terabytes of data was generated. On any given day, you would find more than 10,000 jobs running at these machines.” A terabyte is 1,000 gigabytes.

A team of UT Arlington researchers built a piece of the ATLAS detector. The piece alone cost several million dollars, took three years to construct, weighs more than 50 tons and had to be shipped in more than 100 containers. De is helping install the detector at CERN this fall.

The International Linear Collider represents the next generation of particle accelerators, Dr. White says. Physicists have started the decades-long process to design this facility for the future of high energy physics.

White has proposed a new type of detector for measuring the energies of particles from the collisions of electrons and antielectrons in this collider. He and Assistant Professor Jaehoon Yu are developing this technology to be used in an experiment to further probe the new physics expected from the supercollider at CERN.

These initiatives form a natural extension of UT Arlington’s contributions to the DZero Experiment at Fermilab, which discovered the “top quark” in 1995. DZero studies the interactions of protons and antiprotons at the highest available energies.

Associate Professor Andrew Brandt proposed an addition to this experiment to study cases where protons in high-energy collisions are scattered at small angles but remain intact. The sub-detector for these scattered protons was built at UT Arlington and integrated with the 5,000-ton DZero central detector. This sub-detector is currently taking data and is being used in the thesis analysis of 10 students from four countries.

Also for the DZero Experiment, Dr.  Yu leads a regional computing grid of 12 universities, a further testament to UT Arlington’s emerging presence in grid computing.

And to the High Energy Physics group’s status as major contributors in discovering nature’s fundamental laws.

— Mark Permenter