Lattice gauge theories

In this interview, David Zierler, Oral Historian for AIP, interviews Thomas Appelquist, Eugene Higgins Professor of Physics at Yale University. Appelquist recounts his upbringing in rural Iowa and then Indiana, where he attended Catholic high school. He describes his undergraduate experience at Illinois Benedictine College and explains his attraction to attend a small school for college. Appelquist discusses his decision to attend Cornell for his PhD, and recalls that, relative to others in his cohort who went to larger schools, he had the most catching up to do in quantum mechanics. He explains the development of his thesis topic under the direction of Don Yennie, which focused on aspects of renormalization theory using the Feynman parametric approach. Appelquist contextualizes some of the broader questions in quantum field theory and quantum electrodynamics at this time, and he describes the opportunities that led him to SLAC for his postdoctoral research. He describes his interests there as focused on theories of the weak interactions, and he describes his initial faculty appointment at Harvard where he joined the particle theory group led by Shelly Glashow and Sidney Coleman. Appelquist discusses his close collaboration with Helen Quinn on how to renormalize Yang-Mills theories, and he explains his decision to take a tenured position at Yale in consideration of the culture at Harvard, where the prospects of tenure were minimal. He describes the revolutionary discoveries of asymptotic freedom, QCD, and the “November Revolution” at SLAC and Brookhaven at the time. Appelquist describes his research and administrative activities to advance the particle theory group at Yale, and his overall efforts to improve the department as chair and in particular building up the condensed matter theory group. He discusses his tenure as Dean of the Graduate School and his long-term involvement with the Aspen Center. At the end of the interview, Appelquist describes his current interests in lattice gauge theory and explains why he expects that physics will see double beta decay in the next generation of experiments.

In this interview, David Zierler, Oral Historian for AIP, interviews Marvin Weinstein, Chief Science Officer of Quantum Insights, and emeritus physicist of SLAC. Weinstein describes the origins of Quantum Insights in partnership with David Horn and the development of a data mining algorithm called Dynamic Quantum Clustering (DQC). He recounts his upbringing in Brooklyn, his early interests in physics, and his undergraduate education at Columbia. He describes the big issues in physics at the time, including the two-neutrino experiment, and he explains his decision to remain at Columbia for his PhD to study under Gerald Feinberg. Weinstein explains how he became a postdoctoral student at the Institute of Advanced Study with the endorsement of T.D. Lee to work with Roger Dashen on K13 lepton decays. He describes his subsequent faculty appointments at Yeshiva University and then NYU, and he discusses the opportunities that led to him joining the theory group at SLAC. Weinstein describes his work on PCAC and the Higgs mechanism, and he explains how DQC originated from his interests in quantum mechanics. He explains his subsequent work in lattice field theory and then core and condensed matter physics, and he describes the changing budgetary environment at SLAC over the course of his career. At the end of the interview, Weinstein conveys optimism that his focus on the health industry will demonstrate that the adoption of DQC and its ability to analyze data will lead to better health outcomes across a spectrum of ailments.

In this interview, Junko Shigemitsu, Professor Emerita in the Department of Physics at the Ohio State University, surveys the field of lattice gauge theory over the course of her career, and she recounts her childhood moving around the world because her father was a diplomat for Japan’s foreign ministry. She explains the circumstances that led her family back to Japan, and her decision to pursue a degree in physics at Sophia University in Tokyo. Shigemitsu discusses her interest in attending Cornell for graduate school, where she studied under the direction John Kogut. She discusses Ken Wilson’s revolutionary work on renormalization, and her thesis work on QCD. Shigemitsu describes her postdoctoral work at the Institute for Advanced Study at a time when lattice gauge theory was beginning to mature, and she discusses her subsequent postdoctoral position at Brown. She explains that opportunities that led to her faculty position at Ohio State and her subsequent research on QCD at non-zero temperatures. Shigemitsu discusses the international HPQCD collaboration and more recent advances in understanding subatomic particles in partnership with SLAC and KEK in Japan. She places the greatest excitement in finding physics beyond the Standard Model in the period starting in 2009, and she explains the increasing utility of computers as their power has grown over the decades. At the end of the interview, Shigemitsu conveys her excitement that the field will yield new discoveries, perhaps including new physics, and that quantum computing will likely be central to these prospects. 

Interview with Peter Lepage, Tisch Family Distinguished University Professor of Physics at Cornell. He recounts his childhood in Montreal and his decision to pursue an undergraduate degree in physics at McGill. Lepage discusses his Master’s work at Cambridge University and his decision to do his thesis research in particle physics at Stanford. He describes the fundamental advances happening at SLAC during his graduate years and his work on bound states of electrons and muons under the direction of Stanley Brodsky. Lepage discusses his postdoctoral appointment at Cornell and his work in high-precision QED calculations in atoms, and he describes the foundational impact of Ken Wilson’s work on lattice QCD and the intellectual revolution of renormalization. He describes this period as his entrée into QCD research, and he emphasizes the beauty of Ithaca and the supportive culture of the Physics Department as his main reasons to accept a faculty position at Cornell. Lepage explains how and when computers became central to Lattice QCD research and why effective field theory was an area of specialization that was broadly useful in other subfields. He describes the ongoing stubbornness of the Standard Model, and he discusses his tenure as chair of the department, then as Dean of the College of Arts and Sciences, and his work on PCAST in the Obama administration. Lepage explains his longstanding interest in physics pedagogy, and he discusses his current work on the numerical integration program called VEGAS. In the last part of the interview, Lepage emphasizes that the most fundamental advances in physics are in astrophysics and cosmology and that lattice QCD should be “kept alive” because it’s unclear where it is going until physics goes beyond the Standard Model.

Interview with Wick Haxton, professor of physics at UC Berkeley. Haxton recounts his childhood in Santa Cruz and his early interests in math and science. He describes his undergraduate education at the newly created UC Santa Cruz where his initial interest was in mathematics before he was given the advice that he did “mathematics like a physicist.” Haxton discusses his graduate work at Stanford where his original intent was to study general relativity before he connected with Dirk Walecka and Bill Donnelly to focus on nuclear theory and dense nuclear matter. He discusses his postdoctoral research at the University of Mainz where he concentrated on photo-pion physics during the early days of chiral perturbation theory, and he explains the opportunities that led to his next appointment at the LAMPF facility at Los Alamos. Haxton emphasizes the excellence of both his colleagues and the computational capacity at the Lab, and he describes his faculty appointment at Purdue and the solar neutrino experiment he contributed to in Colorado. He explains the opportunities that led to him joining the faculty at the University of Washington where the DOE was about to fund the Institute for Nuclear Theory. Haxton explains the “breakup” between nuclear theory and particle theory and how the INT addressed that. Haxton discusses the opportunities afforded at the INT to engage in nuclear astrophysics and he explains the rise and fall of the Homestake DUSEL project. He explains his decision to go emeritus at UW and to join the faculty at UC Berkeley and to be dual hatted at the Berkeley Lab, and he describes his tenure as department chair. At the end of the interview, Haxton describes his current work organizing the new Physics Frontier Center and the challenges presented by the pandemic, and he credits his formative time as Los Alamos for the diverse research agenda he has pursued throughout his career.

Interview with Ruth Van de Water, Scientist I at Fermilab. She explains the hierarchical system at the lab to explain her title and she recounts her childhood in Northern Virginia. Van de Water describes her undergraduate experience at William & Mary where she developed an interest in physics and was mentored by David Armstrong, and she describes the considerations that led to her admission to the graduate program at the University of Washington. She discusses her early involvement in the Atlas program and her thesis research that focused on computational and numerical physics and lattice QCD. Van de Water discusses her postdoctoral work at Fermilab, and she describes the state of play regarding the Tevatron and the D0 and CDF collaborations. She describes her ongoing work in lattice QCD research and the opportunity that led to her second postdoctoral position at Brookhaven, where she pursued a new approach to discretizing quarks. Van de Water describes Fermilab “poaching” her back to work on quark flavor physics and become involved in the G-2 experiment. She discusses the negative impact on a decreased budget, and her current leave from Fermilab to be a visiting professor at North Central College, and she shares that she is conflicted about continuing on a strictly research path and focusing more directly on teaching. At the end of the interview, Van de Water discusses the impact of #ShutdownSTEM and the issue of inclusivity in physics and why solutions to under-representation are not easily achievable. 

Interview with Michael Creutz, Senior Physicist Emeritus at Brookhaven National Laboratory. Creutz surveys where lattice gauge theory is “stuck” and where there are promises for breakthroughs in the field. He recounts his birthplace in Los Alamos, where his father was a physicist, and his upbringing in Pittsburgh and then San Diego. Creutz describes his undergraduate education at Caltech and his graduate research at Stanford, where Sid Drell supervised his work on deep inelastic scattering. He explains his decision to take a postdoctoral position at the University of Maryland, and he discusses becoming involved in lattice gauge theory following his exposure to Ken Wilson’s work on renormalization. Creutz describes Brookhaven’s focus on proton scattering when he joined the Lab, and he explains his work during the discovery of the J/psi. He explains his motivation for writing a textbook on lattices, and the value of ever-more powerful computers for lattice gauge research. Creutz explains his “controversial” approach to staggered fermions, and his work on topology in lattice theory. At the end of the interview, Creutz discusses his current interests in chiral symmetry, he reflects on the burst of intellectual activity at the dawn of lattice gauge theory, and he explains why parity violation in neutrinos continues to confound theorists.

In this interview, David Zierler, Oral Historian for AIP, interviews Thomas C. Blum, Professor of Physics at the University of Connecticut. Blum recounts his childhood in Reno, Nevada and he describes his early interests in math and science. He describes his undergraduate work in aeronautical and astronomical engineering at the University of Washington. Blum discusses his job focusing on computational fluid dynamics at Boeing after college and he explains his decision to pursue a Ph.D. in physics at the University of Arizona. He describes his graduate work in lattice gauge theory studying under Doug Toussaint. Blum discusses his postdoctoral work at Brookhaven, where he continued to work on lattice gauge theory, and he describes his decision to join the faculty at UConn. He describes his ongoing interests in chiral symmetry, g-2 and QCD research, and he conveys his excitement over possible future breakthroughs in hadronic vacuum polarization. At the end of the interview, Blum conveys how much fundamental work remains to be done in physics, and as an example he raises what remains an open-ended question: what is the real structure of the proton?