Roberto Peccei, a brilliant theoretical particle physicist who served as UCLA’s vice chancellor for research from 2000 to 2010, died June 1 following a hip fracture. He was 78 and had Parkinson’s disease.

Peccei taught undergraduate and graduate students at UCLA, including in his popular courses on the physics of energy. He served as the dean of the division of physical sciences in the UCLA College from 1993 to 2001.

David Saltzberg, chair of UCLA’s Department of Physics and Astronomy, called him “a giant of theoretical particle physics” who made “monumental achievements and contributions to both science and the university, and who provided sage experience and wisdom in physics, in leadership and in life.”

Peccei, along with Stanford University colleague Helen Quinn, made major contributions to physics, including the Peccei-Quinn Symmetry — an elegant theory that ties together several branches of physics and has important implications for our universe. The Peccei-Quinn Symmetry predicts the existence of very light particles called axions, which may nevertheless be the dominant source of mass in the universe. Axions, the subject of intense experimental and theoretical investigation for four decades, may be the mysterious “dark matter” that account for most of the matter in the universe.

Born in Torino, Italy, in 1942 and raised in Buenos Aires, Argentina, Peccei came to the United States to attend MIT as a physics undergraduate, where he earned his bachelor’s degree in 1962. He earned his master’s at New York University in 1964 and returned to MIT, where he earned his doctorate in physics in 1969. After a brief period of postdoctoral research at the University of Washington, he joined the physics faculty of Stanford University in 1971. In 1978, he joined the staff of the Max Planck Institute for Physics and Astrophysics in Munich, Germany, and from 1987 to 1989 was the head of theory group at one of the largest and most highly respected European laboratories, DESY, in Hamburg.

Peccei joined UCLA’s physics faculty in 1989, where he conducted research in theoretical physics and served in many senior administrative positions.

He was a son of Aurelio Peccei, an Italian industrialist and philanthropist, who was a member of the anti-fascist movement and the resistance during the World War II, then moved to Argentina to oversee Fiat operations in Latin America, and later founded the Club of Rome with the goal of addressing multiple crises facing humanity and the planet. 

“Roberto Peccei was a brilliant scientist, a natural leader, a thoughtful colleague and a special friend,” said his colleague Alexander Kusenko, a UCLA professor of physics and astronomy. “The memory of Roberto Peccei will continue to inspire his colleagues, postdocs and students for many years.”

Kusenko added that as an administrator, Peccei oversaw a significant expansion of UCLA research efforts and the creation of major research institutes on campus.

Speaking of the famous Peccei-Quinn symmetry, Kusenko said, “Interactions of elementary particles, as well as the very existence of matter in the universe, depend on how different the world would be under the hypothetical action of flipping all particle charges and reflecting the world in a mirror. This mathematical transformation is closely related to flipping the arrow of time. It is a long-standing puzzle why the strong interactions, which keep the nuclei together, are unchanged by this transformation. Peccei and Quinn proposed a brilliant explanation based on a new symmetry of nature. This symmetry implies, in particular, the existence of a new particle which has not yet been discovered, but which has the potential to account for dark matter in the universe. Peccei-Quinn symmetry emerges in other areas of physics as well, and has been studied by many scientists.”

Peccei received numerous prizes and awards, including the J.J. Sakurai Prize for Theoretical Particle Physics awarded by the American Physical Society; election as a fellow of the American Association for the Advancement of Science, the UK Institute of Physics and a member of the American Academy of Arts and Sciences.

He also served on many national and international committees on science, as well as the executive committee of the Club or Rome. He served on numerous editorial and advisory boards in the United States and Europe.

Peccei is survived by his wife Jocelyn and their children, Alessandra and Aurelio. In lieu of flowers, the family encourages donations in his honor to the UCLA Department of Physics and Astronomy, as well as to Parkinson’s disease research at UCLA.