University of Texas at Dallas researchers played a role in groundbreaking experiments that led to the discovery of a new elementary particle of matter, one that is “consistent” with the long-sought-after Higgs boson.
When the much-buzzed-about July 4 announcement of the new particle was made by officials at the CERN research facility in Geneva, UT Dallas faculty members, postdoctoral scientists and students involved in the research were positioned around the globe – in China, Australia and Europe.
The research results were so highly anticipated by the scientific community that investigators on-site at CERN, including UT Dallas physics undergraduate student Cyrille Chiari, lined up the night before just to get a seat in the packed auditorium for the early-morning statement.
Dr. Joe Izen
“To give an idea of how motivated people here are, the fire alarm went off and no one moved an inch,” Chiari said in an email. “It went on for 10 minutes and still no one left.”
Chiari is working at CERN’s Large Hadron Collider (LHC) as part of the 2012 CERN Summer Student program. Located on the border between Switzerland and France, the LHC is the world’s most powerful particle accelerator. Scientists use the facility to smash together beams of protons traveling at nearly the speed of light. The energy released from such collisions creates new particles that then break apart and scatter about. Detectors inside the LHC pick up the tracks left behind by the debris, which physicists then analyze to look for clues about the nature of matter. More than 1,700 people from U.S. institutions helped design, build and operate the LHC and its particle detectors.
Dr. Xinchou Lou
Two LHC experiments – abbreviated ATLAS and CMS – provided the data that led to the new particle’s discovery.
While Chiari is spending his summer helping to analyze data from the CMS experiment, Dr. Joe Izen, professor of physics at UT Dallas, is working on the ATLAS experiment, whose detectors he and his team helped build. When the announcement of the new particle was made at CERN, Izen had just come off an 8-hour graveyard shift in the ATLAS control room, so he didn’t get a seat in the auditorium.
“As members of the ATLAS collaboration and professors at UT Dallas, we have had a small part in ushering in the era of Higgs physics. We have the accident of our birthdays to thank that we are still young enough to explore Higgs bosons while we chase other dreams, like dark matter and the fantastic theories that have been concocted to explain it.”
Dr. Joe Izen,
professor of physics,
UT Dallas
“I’m exhilarated and exhausted!” Izen said in an email. He watched the announcement via a webcast, which also was shared live via video link to the International Conference for High Energy Physics in Melbourne, Australia. That’s where Dr. Kendall Reeves, a UT Dallas research scientist, was watching as he prepared to present additional ATLAS data later in the week.
After CERN’s formal announcement about the discovery of the Higgs-boson-like particle, UT Dallas physics professor Dr. Xinchou Lou– who was in Beijing at the Institute of High Energy Physics – helped explain the significance of the discovery to the Chinese news media at a press conference.
In addition to Izen, Lou and Reeves, other members of the UT Dallas ATLAS team include research scientist Dr. Mahsana Ahsan and PhD students Harisankar Namasivayam, Jessica Smith and Brandyn Lee. Team member and physics doctoral student Wei-Cheng Wong defended his dissertation in late June, making him the group’s first PhD graduate.
In the wake of the discovery, Izen reflected on his and Lou’s career-long pursuit of the mysteries of nature, as well as the future prospects for their protégés.
“As members of the ATLAS collaboration and professors at UT Dallas, we have had a small part in ushering in the era of Higgs physics,” Izen said. “We have the accident of our birthdays to thank that we are still young enough to explore Higgs bosons while we chase other dreams, like dark matter and the fantastic theories that have been concocted to explain it.
“I suspect that our postdocs and students working at the LHC this summer might argue that their birth dates are yet more fortunate.”
What’s So Big About the Higgs?
Physicists have been searching for the Higgs boson since its existence was first proposed in 1964. The particle is the final missing piece in the so-called Standard Model, which, through more than four decades of experiments, has correctly explained the elementary particles and forces that make up the visible universe. However, the model needs the Higgs boson and the associated Higgs field to explain how particles acquire mass.
Compared to other elementary particles, the Higgs boson is massive, so it requires the world’s most powerful particle accelerator, the Large Hadron Collider (LHC), to generate the extreme level of energy needed to create the particle.
Once created inside the LHC, the theory goes, the Higgs boson decays into other particles almost immediately, so it can’t be seen directly by detectors. Instead, scientists must comb through the debris to infer that the Higgs was there. Although CERN scientists are highly confident that the new particle announced July 4 is indeed a Higgs boson, they nonetheless characterized the findings as “preliminary,” with a more complete analysis expected later this year.