Obituary of Bruce Winstein (1943-2011)

Bruce Winstein, the Samuel K. Allison Distinguished Service Professor in Physics at the University of Chicago, passed away on Feb. 28, 2011 after a 4-year battle with cancer.

Bruce received his BA in Physics and Mathematics from UCLA in June, 1965, and his PhD from Cal Tech in June of 1970. He then went to the Max Planck Institute in Munich for two years, during which he performed an elegant search for free quarks at the CERN Intersection Storage Rings. In 1972 Bruce came to the University of Chicago as a Senior Research Associate, became an Assistant Professor in 1976, and was awarded tenure in 1980. He spent the year 1985-1986 as a Professor at Stanford and SLAC. In 1997 he was awarded the Samuel K. Allison Distinguished Service Professorship in the Enrico Fermi Institute and Department of Physics.

Starting with his studies of neutral kaon regeneration with Val Telegdi in the 1970s and then with Jim Cronin in the 1980s, Bruce began a systematic investigation of CP-violating neutral kaon decays which culminated in the KTeV series of experiments. In 1999 these administered the coup de grace to the superweak theory of CP violation proposed by Lincoln Wolfenstein shortly after its discovery by Christenson, Cronin, Fitch, and Turlay in 1964.

The KTeV result and a corresponding one from the CERN NA31 and NA48 experiments demonstrated a small but statistically significant difference between the relative rates of decays to two neutral and two charged pions of short-lived (K _S ) and long-lived (K _L ) neutral kaons. This difference was not expected in the superweak theory but consistent with the predictions of the theory of CP violation proposed in 1973 by M. Kobayashi and T. Maskawa, for which they shared the 2008 Nobel Prize with Y. Nambu.

Bruce then turned his attention to cosmology. In his typical disciplined and thoughtful style, he decided to apprentice himself to a working experiment, learning the field from the ground up. He spent the academic year 1999-2000 at Princeton working with the group of Suzanne Staggs on the polarization of the Cosmic Microwave Background Radiation (CMBR).

Bruce went on to form the QUIET collaboration to make very sensitive measurements of the polarization of the CMBR, using the technology of coherent correlation polarimeters. The experiment, which operates on the Chajnantor plateau in the Atacama Desert in Chile, primarily targets the B modes from primordial gravitational waves anticipated from inflation. The combination of signals at two different frequencies, 43 and 95 GHz, provides a sensitive test for possible contamination from diffuse Galactic synchrotron radiation. The QUIET analyses reflect Bruce’s drive to investigate and minimize systematic effects and biases; the power spectra were only examined after a large suite of null tests on the data were passed.

Bruce’s signature style was a meticulous attention to detail while attacking the big questions. The KTeV experiment, for example, addressed the origin of CP violation at the requisite sensitivity. The design was based on minimizing systematics by comparing long-lived and short-lived kaons simultaneously in two neighboring beams, canceling many effects. At the same time the level of understanding the details of the apparatus via comparison of Monte Carlo and data was truly remarkable. The requirement of a ‘blind’ analysis to avoid experimenter-induced bias was one more step in classic experimenting. The same intellectual basis so characteristic of Bruce comes through clearly in the analysis of the QUIET data, which brought the concept of blind analysis to the CMB field.

In 2001 Bruce responded to an NSF competition for national centers by proposing the establishment of a Center for Cosmological Physics at the University of Chicago. The Center, now the Kavli Center for Cosmological Physics, has been a remarkable success. The Center has a very special style, combining cutting-edge detector development to address deep problems, the incubation of superb young folks via fellowships and early responsibility, and collegial interaction, all put in place by Bruce at its founding.

Bruce had many awards recognizing his contributions to science and his leadership roles. He was elected to the National Academy of Sciences in 1995. He was awarded a Guggenheim Fellowship in 1999-2000. In 2003 Bruce was selected as the first annual Distinguished Alumnus of the Physics and Astronomy Department at UCLA. Bruce gave the Bethe Lectures at Cornell in 2004. He was awarded the 2007 W. K. H. Panofsky Prize in Experimental Physics of the American Physical Society. In 2007 he was also elected to Fellowship in the American Association for the Advancement of Science. In addition, Bruce served on a variety of panels charged with advising U.S. Laboratories, the National Science Foundation, and the Department of Energy, including chairing a National Academy of Sciences committee reporting on the status of Elementary Particle Physics in 1995.

Bruce was a dedicated and involved mentor to his students. Some 20 of his former PhD students and postdoctoral scientists are active researchers in physics. Their theses tended to be long and deeply reflective of Bruce’s attention to detail and clear exposition. Bruce’s legacy of intense mentoring will continue through them.

On a personal note, Bruce was a wonderful colleague. His presence was always felt in seminars and meetings. He had strong feelings and very high standards on data, students, and physics. Val Telegdi often made the distinction of physics with a small `p’ and capital-P Physics; Bruce cared deeply about both, and delighted in discussions ranging from details of statistical analysis to the deep questions of the structure of the Universe.

This same intensity, attention to detail, and holding to the highest intellectual standards, was ever-present when Bruce was in the room. He made major contributions to Physics Department and Institute policy through many committees and faculty meetings.

Bruce brought his special intensity and high standards to his areas of interest in his private life. Among other areas, he was a serious stereophile, loved and was very knowledgeable about jazz, and was a life-long serious student of film. As an undergraduate at Cal Tech Bruce founded CinemaTech, the student film society. Bruce taught two special courses at the University of Chicago on the subject ‘Ambiguity and the Nature of Reality in the films of Michelangelo Antonioni.’ In typical Bruce style he met and corresponded with Antonioni. He brought his critical eye and mind to the films, and his authority was widely respected.

Any recalling of Bruce wouldn’t be complete without understanding his sense of humor and his ability to relax and have fun. Bruce was wonderful to have conversations with on wide-ranging topics to top off a day -- he was incisive, expert on so many topics, funny, and warm. Whether it was matter-antimatter asymmetries, the early universe, the much-too-good agreement of data with standard model predictions from the big collider experiments, the change in frequency response of audio cables after freezing, the best recording of a given jazz standard, the role of reflections in Antonioni’s Blowup, the right way to make espresso, how to run a world-class institute, or the merits of his folding bicycle, Bruce was always such a pleasure to talk with. He is sorely missed.