The 2004 Nobel Prize in Physics (Forwarded)

The Royal Swedish Academy of Sciences
Stockholm, Sweden

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Press Release: 5 October 2004

The 2004 Nobel Prize in Physics

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in
Physics for 2004 "for the discovery of asymptotic freedom in the theory of the
strong interaction" jointly to

David J. Gross
Kavli Institute for Theoretical Physics, University of California, Santa
Barbara, USA,

H. David Politzer
California Institute of Technology (Caltech), Pasadena, USA,

and

Frank Wilczek
Massachusetts Institute of Technology (MIT), Cambridge, USA.

A 'colourful' discovery in the world of quarks

What are the smallest building blocks in Nature? How do these particles build up
everything we see around us? What forces act in Nature and how do they actually
function?

This year's Nobel Prize in Physics deals with these fundamental questions,
problems that occupied physicists throughout the 20th century and still
challenge both theoreticians and experimentalists working at the major particle
accelerators.

David Gross, David Politzer and Frank Wilczek have made an important theoretical
discovery concerning the strong force, or the 'colour force' as it is also
called. The strong force is the one that is dominant in the atomic nucleus,
acting between the quarks inside the proton and the neutron. What this year's
Laureates discovered was something that, at first sight, seemed completely
contradictory. The interpretation of their mathematical result was that the
closer the quarks are to each other, the weaker is the 'colour charge'. When the
quarks are really close to each other, the force is so weak that they behave
almost as free particles. This phenomenon is called "asymptotic freedom". The
converse is true when the quarks move apart: the force becomes stronger when the
distance increases. This property may be compared to a rubber band. The more the
band is stretched, the stronger the force.

This discovery was expressed in 1973 in an elegant mathematical framework that
led to a completely new theory, Quantum ChromoDynamics, QCD. This theory was an
important contribution to the Standard Model, the theory that describes all
physics connected with the electromagnetic force (which acts between charged
particles), the weak force (which is important for the sun's energy production)
and the strong force (which acts between quarks). With the aid of QCD physicists
can at last explain why quarks only behave as free particles at extremely high
energies. In the proton and the neutron they always occur in triplets.

Thanks to their discovery, David Gross, David Politzer and Frank Wilczek have
brought physics one step closer to fulfilling a grand dream, to formulate a
unified theory comprising gravity as well -- a theory for everything.

David J. Gross, born 1941 (aged 63) in Washington DC, USA (American citizen).
Doctor's degree in physics in 1966 at the University of California, Berkeley.
Professor at the Kavli Institute for Theoretical Physics at the University of
California, Santa Barbara, USA.

H. David Politzer, (American citizen). Doctor's degree in physics in 1974 at
Harvard University. Professor at the Department of Physics, California Institute
of Technology (Caltech), Pasadena CA, USA.

Frank Wilczek, born 1951 (aged 53) in Queens, New York, USA (American citizen).
Doctor's degree in physics in 1974 at Princeton University. Professor at the
Department of Physics, Massachusetts Institute of Technology (MIT), Cambridge
MA, USA.

Prize amount: SEK 10 million, will be shared equally among the Laureates.

Read more about this year's prize:

* Information for the Public
http://nobelprize.org/physics/laurea...04/public.html
* Advanced Information (pdf)
http://nobelprize.org/physics/laurea...4/phyadv04.pdf
* Links and Further Reading
http://nobelprize.org/physics/laurea...hyreading.html