Gerald Stanford Guralnik, a pioneer of the theory of mass generation, which laid the groundwork for the standard model of particle physics, collapsed following a lecture to new graduates of Brown University’s physics department on 26 April 2014. He died several hours later with Susan, his wife of 50 years, at his bedside. His passing in seemingly good health came as a shock to friends, family, and colleagues, who had expected to enjoy his kindness, wit, and keen physics insights for many years to come. Yet his death came in a setting that exemplified his entire professional life.
Gerry was born in Cedar Falls, Iowa, on 17 September 1936. As fellow Midwesterners, perhaps we were destined to meet and bond, as indeed happened when we were sophomores at MIT. Our relationship continued and broadened during our undergraduate years and beyond, even as he moved to Harvard University in 1958 for graduate work while I continued my studies at MIT.
Among the nonnegotiables in our schedules were the lectures of future Nobelist Julian Schwinger, with whom Gerry shared a deep fascination with upscale fast cars. Schwinger’s perspectives on field theory would provide much of the foundation for the work Gerry and I later did together. Gerry completed his thesis in 1964 under the direction of Walter Gilbert, who went on to receive the Nobel Prize in Chemistry. The topic of his thesis—the photon as a symmetry-breaking solution to field theory—gave Gerry a perspective that guided his early career as well as our collaboration.
As our graduate studies came to an end, we published a paper together—on the subject of Regge poles—that happened to be the first for each of us. The following year we went to Imperial College London, where we joined forces with Tom Kibble, a recent addition to the staff, under the tutelage of Abdus Salam. Our collective attention immediately turned to one of the most baffling questions confronting particle theorists at the time—namely, how to deal with the troubling issue of Goldstone bosons. Although spontaneously broken symmetry (SBS) solutions were coming to be viewed as a promising route to a unified electroweak gauge theory, the deadening hand of the Goldstone theorem blocked progress in that effort. Its prediction that zero-mass particles must occur in any manifestly covariant SBS theory is totally irreconcilable with the world of particle-physics phenomenology.
The approach we ultimately adopted was crucially based on the radiation gauge. It has the immediate advantage of evading the Goldstone theorem by giving up manifest covariance in favor of simple covariance. Schwinger’s lectures on that particular gauge made us hopeful that it could be key to resolving the problem. Application of SBS indeed gave mass to the gauge fields, a result confirmed by the discovery of the W and Z bosons in 1983. Yet the Goldstone boson issue remained; only when we succeeded in displaying in full the banishing of the Goldstone boson from the physical spectrum did we release our results. Contemporaneous efforts in SBS theories by Robert Brout and François Englert and by Peter Higgs gradually caused us to realize that the delay necessitated by the Goldstone issue could loom large in the historical evaluation of those three overlapping but very distinct approaches to SBS. Yet 50 years later there is widespread misunderstanding of the Goldstone boson role, an issue that we recently addressed in what turned out to be Gerry’s last published paper, “Where have all the Goldstone bosons gone?” (Modern Physics Letters A, volume 29, page 1450046, 2014, doi:10.1142/S0217732314500461).
The incorporation of SBS into mainstream particle physics led to many stunning experimental successes and the gradual emergence of the standard model. Eventually, the only thing preventing its general acceptance was the conspicuous absence of a predicted SBS boson—the so-called God particle. Thus was conceived the Large Hadron Collider at CERN with its avowed goal of detecting the elusive boson. Success was announced at CERN on 4 July 2012, an event to which Gerry and I traveled together. (His comparison of the festive atmosphere there to a football game was widely quoted.) Meanwhile, the increasing awareness of work done in 1964 on SBS theory had led the American Physical Society to award the 2010 J. J. Sakurai Prize for Theoretical Particle Physics to Gerry and the five other authors of the three relevant SBS papers. (That sixfold citation remains a record for the society’s awards.) In the many speaking invitations that Gerry later received, he frequently recalled a conversation he had had with Werner Heisenberg in 1965. In that exchange Gerry was told in no uncertain terms that SBS theories could not possibly succeed.
After leaving Imperial College London in 1965, Gerry briefly served as a research associate at the University of Rochester, where he and I continued our SBS collaboration. Then in 1967 he went to Brown, where he was the Chancellor’s Professor of Physics. He continued to be a highly innovative and productive researcher and was an early advocate and user of computers in particle-physics applications. There again he showed his willingness to depart from the orthodoxy of the times, which was long resistant to the introduction of computer technology into theoretical particle physics. He cast a long shadow on the computer systems at Los Alamos National Laboratory, where he spent many years as a consultant and staff member, and at Brown. To the end he continued his collaborations, including with his son, Zachary, who was inspired by his father’s groundbreaking work to pursue the study of particle physics.
