October 7, 2008

Three Win Nobel Prize For Particle Physics Achievements

Two Japanese scientists and a Japanese-born American have been awarded the 2008 Nobel Prize in physics for their work with subatomic particles which provided new insights into the nature of matter.

The Royal Swedish Academy of Sciences announced the winners - Yoichiro Nambu, Makoto Kobayashi and Toshihide Maskawa "“ on Tuesday.

American Yoichiro Nambu, 87, of the University of Chicago, won half of the prize for the discovery of a mechanism called spontaneous broken symmetry in subatomic physics.

The other half of the prize is shared by Kobayashi and Maskawa for discovering the origin of the broken symmetry that predicts the existence of at least three families of quarks in nature.

"Spontaneous broken symmetry conceals nature's order under an apparently jumbled surface," the academy said in its citation. "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."

If the universe were symmetrical, anti-matter would be constantly meeting matter, and exploding.

"Professor Nambu laid a really theoretical foundation for modern particle physics," Sakue Yamada, emeritus professor of the University of Tokyo, told Kyodo news.

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.

The work is highly relevant in relation to upcoming experiments on the Large Hadron Collider (LHC), the recently completed giant accelerator at Cern on the Swiss-French border.

Prior to the 1950s and 60s, it was thought the laws of physics would be invariant - they would look and perform the same in mirrored spatial directions; in forward and reverse time; and between particles and their opposites, anti-particles.

However, further observation in accelerators showed that these symmetric effects were being broken. One of the most important observations was that of a spatial and time inconsistency which is known as CP violation.

"When we wish to build a theory in which broken symmetry is incorporated then we have to add to the theory some aspect, some property of the theory, that distinguishes between particles and anti-particles; and the work of Kobayashi and Maskawa was based on trying to understand the CP violation that was observed; and they postulated there should be more particles than were known at the time," said Jim Stirling, a professor of particle physics at Cambridge University.

"They suggested that in addition to the two generations of quarks known at the time, there should be a third generation; and this was before the third generation was discovered."

The Nobel Prizes - which also cover chemistry, medicine, literature, peace and economics (more properly called the Sveriges Riksbank Prize) - are valued at 10m Swedish Kronor (£800,000; $1.4m).

Nambu will receive 5m Kronor; Kobayashi and Maskawa will share the other half.


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