KU team earns grant to extend leading-edge work at Large Hadron Collider

LAWRENCE — When Philip Baringer was just a graduate assistant working at the Stanford Linear Accelerator Center, his job consisted mostly of lugging around cables and wiring equipment. But he was keen to take a larger role in the experimental particle physics he was witnessing close up.

“I loved the intellectual atmosphere,” Baringer said.

The grunt work paid off. Today, Baringer is a professor of physics and astronomy at the University of Kansas, and has contributed in his career to a pair of revolutionary discoveries in subatomic physics: the top quark, and — most recently — the Higgs Boson.

Indeed, Baringer is a major player in a team of KU particle physicists who recently have earned a three-year, $1.78 million grant from the National Science Foundation to continue its research at the Large Hadron Collider, with Baringer as a principal investigator, along with KU researchers Alice Bean, David Besson and Graham Wilson.

“It’s great to be part of a team that has made a big discovery,” he said. “It’s a great payoff for years of painstaking work.”

Much of the KU team’s work is split between the Large Hadron Collider near Geneva, operated by the European Organization for Nuclear Research (CERN) and Lawrence. When they’re on KU’s campus, often the researchers wake up early for videoconferences with collaborators back at CERN.

“Our research group has two postdocs who live at CERN year-round, so KU has a continual presence there,” Baringer said. “We also have graduate students and undergraduate students who have spent considerable time at CERN. When I’m there, I’m usually meeting with people from our large international collaboration.”

The KU team is helping to design, build and improve components for a pixel detector housed within the Compact Muon Solenoid, a 12,500-ton instrument that tracks particle collisions within the Large Hadron Collider.

“The part of the CMS detector that is closest to the beam collision point is the pixel detector,” said Baringer. “It’s much like the pixels in your digital camera, only it is working in a high-radiation environment and taking hundreds of millions of pictures each second. Because of the radiation environment, the lifetime of this device is limited, and we’re going to have to replace it in a few years. KU is part of the team that is designing the replacement. Alice Bean is the faculty member who is especially involved in this.”

What’s more, the investigators manage KU-based postdoctoral researchers, graduate students, undergraduates (and even some high school students) in the designing and building of components that eventually will play a role in the Large Hadron Collider. Perfecting tools such as a digital module emulator, for testing part the pixel detector design, KU researchers are improving the transfer of information about particle collisions from sensors to the computers that will crunch the data.

“We’re developing a way to get signals from the pixel detector out to the computers where they can be recorded,” Baringer said. “Part of the signal transmission is on copper wire and part on fiber optics. We have a lab in Malott Hall where we have been testing each step in this process of getting the signal from the device to the computer.”

The team from KU is part of a complex organization that includes scientists from all corners of the globe, working together to push forward their understanding of the “Standard Model” of physics, which predicted the existence of the Higgs boson.

“In 2015, the LHC will turn on again at a higher energy — 13 TeV rather than 8 TeV,” Baringer said. “KU hopes to help develop the new detectors, calibrate and operate the detector, and look for new, exciting things in our data analysis. One of many things that interest us is the connection between the Higgs boson and the top quark. The top quark is the most massive elementary particle known. The Higgs is the second most massive and the Higgs field is supposed to provide mass to all particles. So how the Higgs interacts with this most massive of all particles is something we want to study.”

Aside from the work on the collider, the new NSF grant also supports research on cosmic ray physics by KU investigator Besson as well as educating a new crop of young physicists at KU.

“You can think of this grant as helping to train the next generation of scientists,” said Baringer. “The computing techniques, detection hardware and analysis strategies that particle physicists use can be applied to a wide variety of technical problems, so it’s great training no matter what these young scientists end up doing in their careers.”

Ultimately, the work of the KU team could contribute to technological breakthroughs based on the discovery of the Higgs boson and other new understanding of the subatomic structure of the universe.

“Historically, everything we’ve learned about nature at the subatomic scale has proved useful,” Baringer said. “It’s been estimated that a third of the world’s economy came from the discoveries of quantum mechanics  — think computer chips, lasers, designing molecules. I see no reason that trend won’t continue of turning basic research into everyday applications.”