Hugh David Politzer

Hugh D. Politzer is the Richard Chace Tolman Professor of Theoretical Physics at the California Institute of Technology. He was previously a Junior Fellow for the Harvard Society of Fellows (1974-77). He is the recipient of the Nobel Prize for Physics (2004), shared with David Gross and Frank Wilczek. In his first published article, which appeared in 1973, Politzer described the phenomenon of asymptotic freedom: the closer quarks are to each other, the weaker the strong interaction will be between them. When quarks are in extreme proximity, the nuclear force between them is so weak that they behave almost like free particles. This result-independently discovered at around the same time by Gross and Wilczek at Princeton University-was extremely important in the development of quantum chromodynamics. They received the Nobel Prize for this work on how quarks are bound together to form the protons and neutrons of atomic nuclei. With Thomas Appelquist, Politzer also played a central role in predicting the existence of "charmonium," a subatomic particle formed of a charm quark and a charm antiquark. He discovered the asymptotic freedom of non-Abelian gauge theories in 1972, independently of Gross and Wilczek and 't Hooft. Politzer performed early calculations in quantum chromodynamics (QCD) using then-standard field-theoretic methods. He recognized the practical consequences of asymptotic freedom for scattering processes and independently developed the modern QCD parton model. His collaborative work on heavy quark processes was an important precursor to Isgur-Wise symmetry and the Heavy Quark Effective Theory. He has researched chiral perturbation theory, Kaon condensation in nuclear matter, clustering of galaxies, and Bose-Einstein condensation.