The Nobel Prize in Physics 2008

The Nobel Prize in Physics 2008

"for the discovery of the mechanism of spontaneous broken symmetry in subatomic physics"

Yoichiro Nambu
Enrico Fermi Institute, University of Chicago Chicago, IL, USA

"for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature"

Makoto Kobayashi	Toshihide Maskawa
High Energy Accelerator Research Organization (KEK) Tsukuba, Japan	Kyoto Sangyo University; Yukawa Institute for Theoretical Physics (YITP), Kyoto University Kyoto, Japan

The Importance of Asymmetry

Luckily for us, the Universe is not symmetrical, at least at the subatomic level. If it was, the newly formed matter at the Universe's birth would have been annihilated by an equal and opposite amount of antimatter, and nothingness would have resulted. Instead, a small imbalance, or asymmetry, in the amount of matter and antimatter created led to a slight excess of matter, from which we are all eventually formed. Such 'broken symmetry' is one key to our existence

Understanding symmetry, or the lack of it, is an ongoing task, and the 2008 Nobel Prize in Physics rewarded two discoveries concerning symmetry violation in the field of particle physics. In the 1960s Yoichiro Nambu, who had been working on asymmetries underlying superconductivity, was the first to model how broken symmetry can occur spontaneously at the subatomic level. The mathematical descriptions he formulated helped refine the standard model of particle physics, the current working theory that best explains much, but not all, of the way that fundamental particles and the forces that govern their behaviour interact to create the known Universe.

In the early 1970s, Kobayashi and Maskawa formulated a model that explained certain symmetry violations that had recently surprised observers in particle physics experiments. Their model suggested that the collection of subatomic particles known at the time were insufficient to explain the observed behaviours, and predicted the existence of as yet undiscovered elementary particles. It did not, however, specify precisely what form these particles should take. Kobayashi and Maskawa hypothesized the existence of a third family of quarks, which are some of the building blocks from which all matter and antimatter is formed. They then had to wait almost three decades for the experimental results that would verify their hypothesis. The existence of all three families was finally confirmed when the last member was observed in the mid 1990s.

By Adam Smith, Editor-in-Chief, Nobelprize.org

Fuente: nobelprize.org

Nobel Lecture:
Yoichiro Nambu
Spontaneous Symmetry Breaking in Particle Physics: a Case of Cross Fertilization nambu-slides

Makoto Kobayashi
CP Violation and Flavour Mixing
kobayashi-slides

Toshihide Maskawa
What Does CP Violation Tell Us?
maskawa_lecture
First published 8 October 2008