A team involving CU-Boulder was cited for making the first direct observations of a phenomenon known as “time reversal violation” by measuring the rate atomic particles known as B mesons changed quantum states. The measurements essentially confirm that elementary reactions do not run the same forwards as backwards, at least for B mesons. The CU-Boulder team members included physics department faculty members William Ford, Uriel Nauenberg, Jim Smith and Steve Wagner, as well as postdoctoral researcher Alessandro Gaz.
The team analyzed data from the particle physics experiment known as BaBar housed at the SLAC National Accelerator Laboratory in Menlo Park, Calif. The CU physicists performed the analysis for about 25 of the roughly 500 scientific publications generated by research at the facility. Although the facility was shut down in 2008, there were as many as 500 researchers involved during its peak of operation and scientists are still combing through the data generated during the life of the project, said Ford.
In addition, CU-Boulder researchers were involved in detecting the first direct evidence for a new particle that likely is the long sought-after Higgs boson — believed to endow the universe with mass — another top 2012 breakthrough selected by Physics World. Comprised of thousands of scientists, students and support staff working at the European Organization for Nuclear Research, or CERN, the team has been conducting experiments at a facility known as the Large Hadron Collider, or LHC, a 17-mile underground loop below the Swiss-French border in Geneva that is the world’s most powerful atom smasher.
The CU-Boulder high-energy physics team, which includes 15 faculty and students, is involved with the Compact Muon Solenoid, or CMS, one of two massive particle detectors in the LHC and which weighs more than 12,500 tons. The CU team helped design and build the CMS forward pixel detectors — the “eyes” of the device — that help researchers measure the direction and momentum of subatomic particles following collisions, providing clues to their origin and structure.
In addition to Ford, Nauenberg, Smith, Wagner and Gaz, the team included faculty members John Cumulat and Kevin Stenson; postdoctoral researchers Eduardo Luiggi, Keith Ulmer and Shilei Zang; graduate students Brian Drell, Bernadette Heyburn and Andrew Johnson; and technical staff members Eric Erdos and Douglas Johnson.
In the most recent issue of U.S. News & World Report’s America’s Best Graduate Schools, CU-Boulder is tied for first in the nation for its atomic, molecular and optical physics program with the Massachusetts Institute of Technology. In addition, CU-Boulder’s graduate program in quantum physics was ranked fifth in the nation by the magazine.
Physics World is a publication of the Institute of Physics, a worldwide scientific society with a membership of 45,000 and founded to work together to advance physics, education, research and application.