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Scientist

Roberto D. Peccei

1942–2022 · elementary particle physics, theoretical physics

Italian theoretical physicist, together with Helen Quinn proposed the mechanism for solving the strong CP problem in quantum chromodynamics, known as the Peccei–Quinn symmetry. This predicted the existence of axions, hypothetical particles that are prime candidates for dark matter.

Biography

Roberto Peccei was born in Italy in 1942. He graduated from the Massachusetts Institute of Technology (MIT), then worked at Stanford University, the University of California, Los Angeles (UCLA), where he became dean of the physics department and vice-chancellor for research. He made significant contributions to the phenomenology of elementary particle physics. He was a scientific administrator for major projects.

Key discoveries

Peccei–Quinn symmetry (1977) – introduction of a global U(1) symmetry
the spontaneous breaking of which leads to the vanishing of the QCD θ-parameter and explains the absence of CP violation in the strong interaction. Axion
arising as a pseudo-Goldstone boson
naturally becomes a candidate for cold dark matter.

💡 The term 'axion' was coined by Frank Wilczek, inspired by a detergent brand, because the new particle was supposed to 'clean up' the theory of the CP problem.

"He believed that if nature elegantly solves a problem, we should follow that hint."

Concepts

axion dark matter Standard Model

Scientists

Fritz Zwicky Vera Rubin Emilio Gino Segrè Paul Dirac Peter Higgs Richard Feynman J. J. Thomson Marie Curie

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