STOCKHOLM Two Japanese scientists and a Tokyo-born American shared the 2008 Nobel Prize for physics for helping to explain the behavior of subatomic particles, work that has helped shape modern physics theory, the prize committee said on Tuesday.
The Nobel committee lauded Yoichiro Nambu, now of the University of Chicago, and Makoto Kobayashi and Toshihide Maskawa of Japan for work that helped show why the universe is made up mostly of matter and not anti-matter via changes known as broken symmetries.
Nambu's analogy likens the changes to when one dinner guest uses the wrong bread plate, forcing all the other guests at a round table to change as well.
"The work he has done has had implications from the study of the early universe all the way to the behavior of magnetic materials," University of Chicago Provost Thomas Rosenbaum told a news conference.
The three men's work, done in the 1950s through the 1970s, predicted the behavior of the tiny particles known as quarks and underlies the Standard Model, which unites three of the four fundamental forces of nature: the strong nuclear force, weak nuclear force and electromagnetic force.
Nambu also influenced the development of quantum chromodynamics, which describes some interactions between protons and neutrons, which make up atoms, and the quarks that make up the protons and neutrons.
He shared half of the 10 million Swedish crown ($1.4 million) prize with Kobayashi of Japan's High Energy Accelerator Research Organization and Maskawa of Kyoto University.
Kobayashi and Maskawa predicted there were three families of quarks, instead of the two then known. Their calculations played out as predicted in high-energy particle physics experiments and there are now six known types of quarks -- up, down, strange, charm, bottom, and top.
Kobayashi said the news of his Nobel prize came as a shock. "It is my great honor and I can't believe this," he said.
Maskawa said he was not surprised.
"There is a pattern to how the Nobel prize is awarded," he was quoted as saying by Kyodo. "I am very happy that Professor Yoichiro Nambu was awarded. I myself am not that happy."
While his work helps explain how particles shift from one state to the next, Nambu described the initial reaction from his peers as "very poor."
"There was no eureka moment," University of Chicago's James Cronin, the 1980 Nobel laureate in physics, told the news conference.
But, he added, "It has been clear for so many years that of all of the people who have won the Nobel, there has been one missing, and that is Yoichiro Nambu."
Physicists are now searching for the broken symmetry, the Higgs mechanism, which threw the universe into imbalance at the time of the Big Bang 13.7 billion years ago.
Scientists at the Large Hadron Collider at the European Organization for Nuclear Research, or CERN, in Switzerland will be looking for the Higgs particle when they restart the collider in spring 2009.
The prizes, awarded by the Nobel Committee for Physics at the Royal Swedish Academy of Sciences, are given annually for achievements in science, peace, literature and economics.
They were first awarded in 1901 in accordance with the 1895 will of Swedish dynamite millionaire Alfred Nobel.
(Additional reporting by Chisa Fujioka in Tokyo, Michael Kahn in London, John Gress, Mike Conlon and Julie Steenhuysen in Chicago; editing by Maggie Fox and Vicki Allen)