Politzer, Hugh David (1949– )

US physicist. With the US physicists David Gross and Frank Wilczek he shared the Nobel Prize for Physics in 2004 for his contributions to the development of a theory to explain how quark subatomic particles are held together by the strong nuclear force.

Politzer worked independently of his fellow Nobel prizewinners, Gross and Wilczek, to calculate how the strong force acts between subatomic particles known as quarks. Quarks are the building blocks for protons and neutrons in the nucleus of an atom. The standard model of particle physics, that was used to explain how subatomic particle behave, could not account for the observation that quarks could only be made to act as individual particles at very high energies. Politzer discovered that the strong force, also called the colour interaction, acts on quarks to make the attraction between them increase with distance. This has the effect of holding quarks within the nucleus as the forces of attraction increase the further away quarks move from each other. The discovery was published in two scientific papers in 1971 and formed the basis of the theory of colour interaction known as quantum chromodynamics (QCD). This work allowed the standard model of particle physics to be completed.

Politzer was born in New York City. He was awarded his bachelor of science degree from the University of Michigan, Ann Arbor in 1969 and his PhD in physics from Harvard University, Cambridge, Massachusetts in 1974. After graduation he joined the staff at the California Institute of Technology (Caltech), Pasadena, California. As of 2004 he held the position of professor of theoretical physics at the department of physics at Caltech.