American, 2 Japanese share Nobel Prize in physics

— -- Insights into the peculiarities of the smallest subatomic particles and the existence of the universe have netted one American and two Japanese theorists the 2008 Nobel Prize in physics.

The Royal Swedish Academy of Sciences Tuesday awarded half of the $1.4 million prize to Yoichiro Nambu, 87, of the University of Chicago and the remainder to Makoto Kobayashi, 64, of Japan's High Energy Accelerator Research Organization and Toshihide Maskawa, 68, of Kyoto University for "deeper understanding of what happens far inside the tiniest building blocks of matter."

"I was surprised, I did not expect it," Nambu said. "My wife didn't believe it for 30 minutes."

In 1960, Nambu introduced particle physics to the idea of spontaneous symmetry-breaking to explain why subatomic particles might be driven to favor particular values of intrinsic magnetism or electrical charge, rather than symmetrically favoring all values equally.

"I think the award to Nambu is long overdue," says Steven Weinberg of the University of Texas-Austin, who won the Nobel for physics in 1979. "He was the first to realize the importance of spontaneous symmetry breaking," which "allows you to see that beneath the apparent messiness of nature, there is an underlying simplicity."

Nambu's work contributed to the discovery of quarks, the sub-atomic particles hidden inside the protons and neutrons at the center of atoms.

In turn, Kobayashi and Maskawa in 1973 explored more broken symmetry, the predominance of matter over antimatter.

Antimatter, a form of matter not found ouWith public interest in particle physics piqued by September's start-up of Europe's Large Hadron Collider, the world's largest atom-smasher, Dylla said the Nobel Prize "points to the groundwork for the physics we'll be seeing in the next few years."

Kobayashi and Maskawa predicted the existence of the "top" and "bottom" quarks in research that "ranks among the 100 most cited papers in physics in the last century," says science historian David Pendlebury.

Quarks come in pairs and triplets, and in this case, the discovery of the new quark pair fully explained radioactivity.

In the award announcement, the Swedish academy said the Japanese theorists' work contributed to an understanding of why more matter than antimatter appeared in the Big Bang: "One extra particle of matter for every 10 billion particles of antimatter was enough to make our world survive. This excess of matter was the seed of our whole universe, which filled with galaxies, stars and planets — and eventually life."

Physicist H. Frederick Dylla, head of the American Institute of Physics, said, "Such fundamental discoveries, which have laid the groundwork for experiments that themselves later won the Nobel, suggest the award this year was long overdue."