Particle Physicists Get Nobel

An American and two Japanese physicists whose theoretical insights have provided a deeper understanding of what happens inside the tiniest building blocks of matter will share the Nobel Prize in Physics for 2008, the Royal Swedish Academy of Sciences announced Tuesday.

Receiving one half of the approximately $1.3 million award is Yoichiro Nambu of the Enrico Fermi Institute at the University of Chicago. Nambu, born in Tokyo and a US citizen, was honored for his discovery of the mechanism of spontaneous broken symmetry in subatomic physics, the academy said.

Splitting the other half of the award is Makoto Kobayashi, professor emeritus, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan; and Toshihide Maskawa, professor emeritus, Yukawa Institute for Theoretical Physics (YITP), Kyoto University, Japan, for their discovery of the origin of the borken symmetry which predicts the existence of at least three families of quarks in nature.

The theoretical work of Nambu, Kobayashi and Maskawa concerned nature's laws of symmetry, or broken symmetries. Symmetry was broken in the universe shortly after the Big Bang some 14 billion years ago when nearly as much antimatter as matter was created. A tiny, microscopic deviation from perfect symmetry -- one extra particle of matter for every 10 billion particles of antimatter -- was enough to plant the seeds of life in our universe. What lies behind this symmetry violation still remains a major mystery and an active field of research. The particle physics community is hoping that the Large Hadron Collider at CERN in Geneva will be able to provide some answers once it is in operation next year.

As early as 1960, Nambu formulated his mathematical description of spontaneous broken symmetry in elementary particle physics. Spontaneous broken symmetry conceals nature’s order under an apparently jumbled surface. It has proved to be extremely useful, and Nambu’s theories permeate the Standard Model of elementary particle physics. The model unifies the smallest building blocks of all matter and three of nature’s four forces in one single theory.

The spontaneous broken symmetries that Nambu studied, differ from the broken symmetries described by Kobayashi and Maskawa. These spontaneous occurrences seem to have existed in nature since the very beginning of the universe and came as a complete surprise when they first appeared in particle experiments in 1964. It is only in recent years that scientists have come to fully confirm the explanations that Kobayashi and Maskawa made in 1972. It is for this work that they were awarded the Nobel Prize.

Kobayashi and Maskawa explained broken symmetry within the framework of the Standard Model, but required that the model be extended to three families of quarks. These predicted, hypothetical new quarks have recently appeared in physics experiments. As late as 2001, the two particle detectors (BaBar at Stanford and Belle at Tsukuba) both detected broken symmetries independently of each other. The results were exactly as Kobayashi and Maskawa had predicted almost three decades earlier.

For more information, visit: www.nobelprize.org