Iowa State scientists, students contribute to world's biggest science experiment

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The first beam of protons will begin racing around the world's biggest science experiment on Wednesday, Sept. 10, and Iowa State University physicists will be part of the research team taking notes. They'll also be joining physicists around the world in celebrating a major milestone for the $8 billion, 17-miles-around Large Hadron Collider, the most powerful particle accelerator ever built.

The collider will accelerate beams of protons or lead ions to nearly the speed of light and crash them together. Detectors will collect data about the paths, energies and identities of the particles that fly from the collisions. Researchers hope the experiments answer some basic questions about how the universe works: How do the particles that make up atoms acquire mass? What is dark matter? What happened to antimatter? What was it like just after the big bang?

Iowa State physicists will help answer those questions by working in a control room at CERN, the European Organization for Nuclear Research near Geneva, Switzerland, the home of the collider. Iowa State physicists are also working on the pixel detector, the innermost part of the collider's ATLAS detector, one of two huge (it's 46 meters long and 25 meters high) general-purpose detectors at the collider. And Iowa State physicists are working to coordinate American analysis of data from the ATLAS detector.

The new collider will also provide plenty of data for Iowa State researchers studying subatomic particles called top quarks. Quarks are the basic building blocks of protons and neutrons; top quarks are the heaviest and last of the quarks to be discovered.

"The Large Hadron Collider is going to be a factory for producing top quarks," said Eli Rosenberg, an Iowa State professor of physics and astronomy who collaborated on the ATLAS detector project and is currently on assignment with the U.S. Department of Energy.

Physicists are also hoping the new collider will produce evidence of something they've never detected before. That's the Higgs boson, a particle predicted by the Standard Model of particle physics. The model theorizes that space is filled with a Higgs field and particles acquire their masses by interacting with the field.

Detecting the Higgs could answer basic questions about why matter has mass and how particles acquire mass.

"We have a theory for generating mass that works well," Rosenberg said. "We think this particle is why things have mass, but it may be more complicated than that."

The team of Iowa State physicists preparing to look for answers in all the data produced by the collider includes Jim Cochran, an associate professor of physics and astronomy who's leading the group that will oversee American analysis of data from the collider; H. Bert Crawley, a professor of physics and astronomy; Soeren Prell, an associate professor of physics and astronomy; and W. Thomas Meyer, an adjunct research professor of physics and astronomy. Ulysses Grundler, a postdoctoral research associate in physics and astronomy, plus Andrew Nelson and Nathan Triplett, graduate students in physics and astronomy, are based at the collider. Graduate students Kyoko Yamanaka, Alaettin Serhan Mete and Suyog Shrestha will also be involved in the project.

Iowa State researchers are using more than $500,000 per year from a larger U.S. Department of Energy grant to support their work with the Large Hadron Collider.

The Iowa State researchers are among more than 10,000 scientists and engineers from 500 schools and companies working on the Large Hadron Collider. Cochran said high energy physics has a long history of building the huge international collaborations that make it possible to run the biggest science experiments on earth.

Source: Iowa State University