William Allan Bardeen (born September 15, 1941, in Washington, Pennsylvania) is an American theoretical physicist who worked at the Fermi National Accelerator Laboratory.
He also played a major role in developing a theory of dynamical breaking of electroweak symmetry via top quark condensates, leading to the first composite Higgs models.
He also developed an analytic, non-perturbative approach for the calculation of non-leptonic decays of Kaons, known as Dual QCD.
Bardeen is considered one of the world's leading authorities on quantum field theory in its application to real-world physical phenomena.
In 1975, Bardeen joined the staff of the Fermi National Accelerator Laboratory where he has served as Head of the Theoretical Physics Department from 1987-1993 and 1994-1996.
[1] From 1993-1994, he was Head of Theoretical Physics at the SSC Laboratory before the project was terminated by act of Congress.
Bardeen lives in Warrenville, Illinois, with his wife Marge, who was manager of the Education Department at Fermilab.
[2] He has two grown children: Charles a retired Project Scientist at the National Center for Atmospheric Research, Boulder, CO, and Karen, who taught chemistry at Oak Park and River Forest High School, Oak Park, Illinois.
Bardeen is co-inventor of the theory of the chiral anomaly, which is of foundational importance in modern theoretical physics.
[4] This proves that the anomaly coefficient is not subject to renormalization to all orders in perturbation theory and anticipates the fact that it is associated with topological index theorems.
Bardeen, in a tour de force, computed the full, nontrivial structure of the chiral anomaly in non-abelian Yang-Mills gauge theories.
[9] On sabbatical, working at CERN in 1971, Bardeen collaborated with Murray Gell-Mann, Harald Fritzsch, and Heinrich Leutwyler.
[10] With his colleagues Andrzej Buras, Dennis Duke and Taizo Muta, Bardeen helped to formulate perturbation theory for quantum chromodynamics, introducing the systematic
scheme for loop-level perturbation theory, frequently used in the analysis of QCD processes in high energy experiments.
[11] With Buras and Jean-Marc Gerard he developed an analytical, non-perturbative framework for the calculation of non-leptonic decays of K-mesons and
The theory, developed with Christopher T. Hill and Manfred Lindner, predicted a heavy top quark, governed by the infrared fixed point (about 20% heavier than the observed top quark mass of 175 GeV), but it tended to predict too heavy a Higgs boson, almost twice the observed mass of 125 GeV.
Nonetheless, this was the first composite Higgs boson model and the general idea remains an intriguing possibility.
[16] This correctly predicted an abnormally long-lived resonance ten years before it was discovered by the BABAR collaboration: the
The theory was further developed by Bardeen, Hill and Estia Eichten, and various decay modes were predicted that have been confirmed by experiment.
In 1985, Bardeen was awarded a John S. Guggenheim Memorial Foundation Fellowship for research on the application of quantum field theory to elementary particle physics.
Bardeen was awarded the 1996 J.J. Sakurai Prize of the American Physical Society for his work on anomalies and perturbative quantum chromodynamics.