Elusive particles found

IN THE PAST YEAR, PRINCETON PHYSICISTS have detected two particles that were predicted decades ago to exist but had not been found until now. Both particles were detected using a scanning-tunneling microscope to image the particles inside a crystal. The particles may someday enable powerful computers based on quantum mechanics.

A team led by Ali Yazdani, the Class of 1909 Professor of Physics, detected the “Majorana fermion,” which behaves simultaneously like matter and antimatter and was first proposed in 1937 by Italian physicist Ettore Majorana. The team, which received funding from the National Science Foundation and the Office of Naval Research, included B. Andrei Bernevig, an associate professor of physics, and other colleagues at Princeton and at the University of Texas-Austin. They published their results in the Oct. 2, 2014, issue of the journal Science.

A few months later, an international team led by M. Zahid Hasan, professor of physics, detected another elusive particle, the “Weyl fermion,” first theorized by the mathematician and physicist Hermann Weyl in 1929. The particle is massless and can also behave like matter and antimatter. The research team, which received support from the Gordon and Betty Moore Foundation and the U.S. Department of Energy, published their work in Science on July 16, 2015.

–By Steven Schultz and Morgan Kelly

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Higgs boson, confirmed

Several Princeton faculty members and students were directly involved in the search for the once-elusive particle known as the Higgs boson. Last March, physicists at the world’s largest particle accelerator, the Large Hadron Collider on the border of France and Switzerland, presented the best evidence yet for the detection of the particle, which is thought to be essential for giving mass to the universe and was the subject of the 2013 Nobel Prize in Physics.

-By Catherine Zandonella